Implement #624: Use shorter hashes with CPM_SOURCE_CACHE (#631)

* Add ASSERT_CONTENTS_EQUAL test macro in testing.cmake

Checks if the contents of a file matches the given input

* Use shorter hashes with CPM_SOURCE_CACHE (#624)

Uses shorter hashes with CPM_SOURCE_CACHE. Falls back to a longer hash
if necessary (ie, if there's a collision with an existing hash).

See: https://github.com/cpm-cmake/CPM.cmake/issues/624

* Update integration tests to support shorter hashes

* trigger ci

* run cmake-format

* if already available, use the legacy cache hash

* create temporary file in current binary dir

* add test case for legacy hash

---------

Co-authored-by: Lars Melchior <lars.melchior@gmail.com>
Co-authored-by: Lars Melchior <TheLartians@users.noreply.github.com>

.cmake-format

@@ -1,73 +1,5 @@
+include: ["cmake/.cmake-format-additional_commands-cpm"]
 format:
   tab_size: 2
   line_width: 100
   dangle_parens: true
-
-parse:
-  additional_commands:
-    cpmaddpackage:
-      pargs:
-        nargs: '*'
-        flags: []
-      spelling: CPMAddPackage
-      kwargs: &cpmaddpackagekwargs
-        NAME: 1
-        FORCE: 1
-        VERSION: 1
-        GIT_TAG: 1
-        DOWNLOAD_ONLY: 1
-        GITHUB_REPOSITORY: 1
-        GITLAB_REPOSITORY: 1
-        GIT_REPOSITORY: 1
-        SVN_REPOSITORY: 1
-        SVN_REVISION: 1
-        SOURCE_DIR: 1
-        DOWNLOAD_COMMAND: 1
-        FIND_PACKAGE_ARGUMENTS: 1
-        NO_CACHE: 1
-        GIT_SHALLOW: 1
-        URL: 1
-        URL_HASH: 1
-        URL_MD5: 1
-        DOWNLOAD_NAME: 1
-        DOWNLOAD_NO_EXTRACT: 1
-        HTTP_USERNAME: 1
-        HTTP_PASSWORD: 1
-        EXCLUDE_FROM_ALL: 1
-        SOURCE_SUBDIR: 1
-        OPTIONS: +
-    cpmfindpackage:
-      pargs:
-        nargs: '*'
-        flags: []
-      spelling: CPMFindPackage
-      kwargs: *cpmaddpackagekwargs
-    cpmdeclarepackage:
-      pargs:
-        nargs: '*'
-        flags: []
-      spelling: CPMDeclarePackage
-      kwargs: *cpmaddpackagekwargs
-    packageproject:
-      pargs:
-        nargs: '*'
-        flags: []
-      spelling: packageProject
-      kwargs:
-        NAME: 1
-        VERSION: 1
-        INCLUDE_DIR: 1
-        INCLUDE_DESTINATION: 1
-        BINARY_DIR: 1
-        COMPATIBILITY: 1
-        VERSION_HEADER: 1
-        DEPENDENCIES: +
-    cpmusepackagelock:
-      pargs: 1
-      spelling: CPMUsePackageLock
-    cpmregisterpackage:
-      pargs: 1
-      spelling: CPMRegisterPackage
-    cpmgetpackageversion:
-      pargs: 2
-      spelling: CPMGetPackageVersion

.git_archival.txt

@@ -0,0 +1,3 @@
+node: $Format:%H$
+node-date: $Format:%cI$
+describe-name: $Format:%(describe:tags=true,match=?[0-9.]*)$

.gitattributes

@@ -0,0 +1 @@
+.git_archival.txt  export-subst

.github/workflows/examples.yaml

@@ -12,7 +12,7 @@ jobs:
   gcc:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: build all
         env:
           CC: gcc
@@ -22,7 +22,7 @@ jobs:
   clang:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: build all
         env:
           CC: clang

.github/workflows/macos.yml

@@ -1,22 +0,0 @@
-name: MacOS
-
-on:
-  push:
-    branches:
-      - master
-  pull_request:
-    branches:
-      - master
-
-jobs:
-  build:
-
-    runs-on: macos-latest
-    
-    steps:
-    - uses: actions/checkout@v1
-    
-    - name: run tests
-      run: |
-        cmake -Htest -Bbuild/test
-        cmake --build build/test --target test-verbose

.github/workflows/publish.yaml

@@ -10,13 +10,14 @@ jobs:
     name: Publish CPM.cmake
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v3
 
       - name: Set CPM version by tag
         run: |
           mkdir dist
-          sed "s/1.0.0-development-version/${GITHUB_REF/refs\/tags\/v}/g" cmake/CPM.cmake > dist/CPM.cmake
+          sed -e "s/1.0.0-development-version/${GITHUB_REF/refs\/tags\/v}/g" cmake/CPM.cmake > dist/CPM.cmake
-          sed "s/1.0.0-development-version/${GITHUB_REF/refs\/tags\/v}/g" cmake/get_cpm.cmake > dist/get_cpm.cmake
+          sed -e "s/1.0.0-development-version/${GITHUB_REF/refs\/tags\/v}/g" \
+              -e "s/CPM_HASH_SUM_PLACEHOLDER/$(sha256sum dist/CPM.cmake | cut -d' ' -f1)/" cmake/get_cpm.cmake > dist/get_cpm.cmake
 
       - name: Upload CPM.cmake to release
         uses: svenstaro/upload-release-action@v1-release

.github/workflows/style.yaml

@@ -0,0 +1,31 @@
+name: Style
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  style:
+
+    runs-on: ubuntu-latest
+    
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Setup cmake
+      uses: jwlawson/actions-setup-cmake@v1.13
+      with:
+        cmake-version: '3.27.x'
+    
+    - name: Install format dependencies
+      run: pip3 install clang-format==14.0.6 cmake_format==0.6.11 pyyaml
+
+    - name: configure
+      run: cmake -Stest/style -Bbuild/style
+
+    - name: check style
+      run: cmake --build build/style --target check-format

.github/workflows/style.yml

@@ -1,28 +0,0 @@
-name: Style
-
-on:
-  push:
-    branches:
-      - master
-  pull_request:
-    branches:
-      - master
-
-jobs:
-  style:
-
-    runs-on: macos-latest
-    
-    steps:
-    - uses: actions/checkout@v1
-    
-    - name: Install format dependencies
-      run: |
-        brew install clang-format
-        pip3 install cmake_format==0.6.11 pyyaml
-
-    - name: configure
-      run: cmake -Htest/style -Bbuild/style
-
-    - name: check style
-      run: cmake --build build/style --target check-format

.github/workflows/test.yaml

@@ -0,0 +1,48 @@
+name: Test
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  tests:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        # windows-latest is windows-2019 which carries a pretty old version of ruby (2.5)
+        # we need at least ruby 2.7 for the tests
+        # instead of dealing with installing a modern version of ruby on 2019, we'll just use windows-2022 here
+        os: [ubuntu-latest, windows-2022, macos-latest]
+        # we want to ensure compatibility with a recent CMake version as well as the lowest officially supported
+        # legacy version that we define as the default version of the second-latest Ubuntu LTS release currently available
+        cmake_version: ['3.16.3', '3.27.5', '3.30.0']
+        exclude:
+          # there seems to be an issue with CMake 3.16 not finding a C++ compiler on windows-2022 
+          - os: windows-2022
+            cmake_version: '3.16.3'
+
+    steps:
+      - name: clone
+        uses: actions/checkout@v3
+
+      - name: Setup cmake
+        uses: jwlawson/actions-setup-cmake@v1.13
+        with:
+          cmake-version: ${{ matrix.cmake_version }}
+
+      - name: unit tests
+        run: |
+          cmake -Stest -Bbuild/test
+          cmake --build build/test --target test-verbose
+        env:
+          CMAKE_VERSION: ${{ matrix.cmake_version }}
+
+      - name: integration tests
+        run: ruby test/integration/runner.rb
+        env:
+          CPM_INTEGRATION_TEST_DIR: ./build/integration
+          CMAKE_VERSION: ${{ matrix.cmake_version }}

.github/workflows/ubuntu.yml

@@ -1,29 +0,0 @@
-name: Ubuntu
-
-on:
-  push:
-    branches:
-    - master
-  pull_request:
-    branches:
-    - master
-
-jobs:
-  build:
-
-    runs-on: ubuntu-latest
-    
-    steps:
-    - uses: actions/checkout@v1
-    
-    - name: install updates
-      run: |
-        wget -O cmake.sh https://cmake.org/files/v3.14/cmake-3.14.0-Linux-x86_64.sh 
-        sudo sh cmake.sh --skip-license --exclude-subdir --prefix=/usr/local
-        export PATH=/usr/local/bin:$PATH
-        cmake --version
-    
-    - name: run tests
-      run: |
-        cmake -Htest -Bbuild/test
-        cmake --build build/test --target test-verbose

.github/workflows/windows.yml

@@ -1,22 +0,0 @@
-name: Windows
-
-on:
-  push:
-    branches:
-    - master
-  pull_request:
-    branches:
-    - master
-
-jobs:
-  build:
-
-    runs-on: windows-latest
-    
-    steps:
-    - uses: actions/checkout@v1
-    
-    - name: run tests
-      run: |
-        cmake -Htest -Bbuild/test
-        cmake --build build/test --target test-verbose

CMakeLists.txt

@@ -0,0 +1,28 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+if(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/.git/")
+  find_package(Git REQUIRED)
+  execute_process(
+    COMMAND "${GIT_EXECUTABLE}" describe --tags --match=?[0-9.]*
+    WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}"
+    OUTPUT_VARIABLE DESCRIBE_NAME COMMAND_ERROR_IS_FATAL ANY
+  )
+  set(CPM_DEVELOPMENT "-development-version")
+else()
+  file(STRINGS "${CMAKE_CURRENT_SOURCE_DIR}/.git_archival.txt" DESCRIBE_NAME
+       REGEX "^describe-name:.*"
+  )
+endif()
+
+string(REGEX MATCH "([0-9\\.]+)" EXTRACTED_CPM_VERSION "${DESCRIBE_NAME}")
+
+project(
+  CPM.cmake
+  VERSION "${EXTRACTED_CPM_VERSION}"
+  DESCRIPTION
+    "CMake's missing package manager. A small CMake script for setup-free, cross-platform, reproducible dependency management."
+  HOMEPAGE_URL "https://github.com/cpm-cmake/CPM.cmake"
+  LANGUAGES NONE
+)
+
+include("${CMAKE_CURRENT_SOURCE_DIR}/cmake/CPM.cmake")

CONTRIBUTING.md

@@ -0,0 +1,177 @@
+<!-- omit in toc -->
+# Contributing to CPM.cmake
+
+First off, thanks for taking the time to contribute! ❤️
+
+All types of contributions are encouraged and valued. See the [Table of Contents](#table-of-contents) for different ways to help and details about how this project handles them. Please make sure to read the relevant section before making your contribution. It will make it a lot easier for us maintainers and smooth out the experience for all involved. The community looks forward to your contributions. 🎉
+
+> And if you like the project, but just don't have time to contribute, that's fine. There are other easy ways to support the project and show your appreciation, which we would also be very happy about:
+> - Star the project
+> - Tweet about it
+> - Refer this project in your project's readme
+> - Mention the project at local meetups and tell your friends/colleagues
+
+<!-- omit in toc -->
+## Table of Contents
+
+- [I Have a Question](#i-have-a-question)
+- [I Want To Contribute](#i-want-to-contribute)
+- [Reporting Bugs](#reporting-bugs)
+- [Suggesting Enhancements](#suggesting-enhancements)
+- [Your First Code Contribution](#your-first-code-contribution)
+- [Styleguides](#styleguides)
+
+
+
+## I Have a Question
+
+> If you want to ask a question, we assume that you have read the available [Documentation](https://github.com/cpm-cmake/CPM.cmake/blob/master/README.md).
+
+Before you ask a question, it is best to search for existing [Issues](https://github.com/cpm-cmake/CPM.cmake/issues) that might help you. In case you have found a suitable issue and still need clarification, you can write your question in this issue. It is also advisable to search the internet for answers first.
+
+If you then still feel the need to ask a question and need clarification, we recommend the following:
+
+- Open an [Issue](https://github.com/cpm-cmake/CPM.cmake/issues/new).
+- Provide as much context as you can about what you're running into.
+- Provide project and platform versions (CMake, OS, etc), depending on what seems relevant.
+
+We will then take care of the issue as soon as possible.
+
+## I Want To Contribute
+
+> ### Legal Notice <!-- omit in toc -->
+> When contributing to this project, you must agree that you have authored 100% of the content, that you have the necessary rights to the content and that the content you contribute may be provided under the project license.
+
+### Reporting Bugs
+
+<!-- omit in toc -->
+#### Before Submitting a Bug Report
+
+A good bug report shouldn't leave others needing to chase you up for more information. Therefore, we ask you to investigate carefully, collect information and describe the issue in detail in your report. Please complete the following steps in advance to help us fix any potential bug as fast as possible.
+
+- Make sure that you are using the latest version.
+- Determine if your bug is really a bug and not an error on your side e.g. using incompatible environment components/versions (Make sure that you have read the [documentation](https://github.com/cpm-cmake/CPM.cmake/blob/master/README.md). If you are looking for support, you might want to check [this section](#i-have-a-question)).
+- To see if other users have experienced (and potentially already solved) the same issue you are having, check if there is not already a bug report existing for your bug or error in the [bug tracker](https://github.com/cpm-cmake/CPM.cmake/issues?q=label%3Abug).
+- Also make sure to search the internet (including Stack Overflow) to see if users outside of the GitHub community have discussed the issue.
+- Collect information about the bug:
+- Stack trace / Full CMake error output
+- OS, Platform and Version (Windows, Linux, macOS, x86, ARM)
+- Version of CMake, compiler or other tools used, depending on what seems relevant.
+- Possibly any relevant environment / command line arguments used
+- Can you reliably reproduce the issue? And can you also reproduce it with older versions?
+
+<!-- omit in toc -->
+#### How Do I Submit a Good Bug Report?
+
+We use GitHub issues to track bugs and errors. If you run into an issue with the project:
+
+- Open an [Issue](https://github.com/cpm-cmake/CPM.cmake/issues/new). (Since we can't be sure at this point whether it is a bug or not, we ask you not to talk about a bug yet and not to label the issue.)
+- Explain the behavior you would expect and the actual behavior.
+- Please provide as much context as possible and describe the *reproduction steps* that someone else can follow to recreate the issue on their own. This usually includes your code. For good bug reports you should isolate the problem and create a reduced test case.
+- Provide the information you collected in the previous section.
+
+Once it's filed:
+
+- The project team will label the issue accordingly.
+- A team member will try to reproduce the issue with your provided steps. If there are no reproduction steps or no obvious way to reproduce the issue, the team will ask you for those steps and mark the issue as `needs-repro`. Bugs with the `needs-repro` tag will not be addressed until they are reproduced.
+- If the team is able to reproduce the issue, it will be marked `needs-fix`, as well as possibly other tags (such as `critical`), and the issue will be left to be [implemented by someone](#your-first-code-contribution).
+
+### Suggesting Enhancements
+
+This section guides you through submitting an enhancement suggestion for CPM.cmake, **including completely new features and minor improvements to existing functionality**. Following these guidelines will help maintainers and the community to understand your suggestion and find related suggestions.
+
+<!-- omit in toc -->
+#### Before Submitting an Enhancement
+
+- Make sure that you are using the latest version.
+- Read the [documentation](https://github.com/cpm-cmake/CPM.cmake/blob/master/README.md) carefully and find out if the functionality is already covered, maybe by an individual configuration.
+- Perform a [search](https://github.com/cpm-cmake/CPM.cmake/issues) to see if the enhancement has already been suggested. If it has, add a comment to the existing issue instead of opening a new one.
+- Find out whether your idea fits with the scope and aims of the project. It's up to you to make a strong case to convince the project's developers of the merits of this feature. Keep in mind that we want features that will be useful to the majority of our users and not just a small subset. If you're just targeting a minority of users, consider writing an add-on/plugin library.
+
+<!-- omit in toc -->
+#### How Do I Submit a Good Enhancement Suggestion?
+
+Enhancement suggestions are tracked as [GitHub issues](https://github.com/cpm-cmake/CPM.cmake/issues).
+
+- Use a **clear and descriptive title** for the issue to identify the suggestion.
+- Provide a **step-by-step description of the suggested enhancement** in as many details as possible.
+- **Describe the current behavior** and **explain which behavior you expected to see instead** and why. At this point you can also tell which alternatives do not work for you.
+- **Explain why this enhancement would be useful** to most CPM.cmake users. You may also want to point out the other projects that solved it better and which could serve as inspiration.
+
+### Your First Code Contribution
+
+Please try to keep your individual changes as minimal and focussed on the issue as possible.
+If you discover that the scope of your contribution is growing larger than expected you might want to split the changes into multiple separate contributions to allow a more focussed discussion and review.
+
+It is usually a great idea and often required to add tests for your changes.
+This allows us to quickly validate that the changes are working as intended and also guarantees that they won't be broken by other future updates.
+For small and targeted functional changes, e.g. supporting a new URL schema, a [unit test](#unit-tests) may be enough.
+For contributions that change large-scale behaviour, such as dependency caching features, an [integration test](#integration-tests) is more suited.
+Depending on the changes, a combination of both test types may also be appropriate.
+
+#### Unit tests
+
+Unit tests are small CMake scripts that live in the [unit test directory](./test/unit/).
+They usually make use of some of the helper assertions defined in the [testing.cmake](./cmake/testing.cmake) file.
+An example unit test for checking the `cpm_get_version_from_git_tag` function could look like the following.
+
+```cmake
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+include(${CPM_PATH}/CPM.cmake)
+include(${CPM_PATH}/testing.cmake)
+
+cpm_get_version_from_git_tag("v1.2.3-a" VERSION)
+assert_equal("1.2.3" ${VERSION})
+```
+
+This test can be run directly with CMake by providing the CPM source directory.
+
+```bash
+cmake -DCPM_PATH=$(pwd)/cmake -P <path to the test file>
+```
+
+We can also the [test directory's](./test/) CMakeLists to detect and run all unit tests using CMake's test runner.
+
+```bash
+cmake -Stest -Bbuild/test
+cmake --build build/test --target test-verbose # or `test` for less noisy output 
+```
+
+#### Integration tests
+
+The integration tests of CPM.cmake are written in Ruby. They use a custom integration test framework which extends the [Test::Unit](https://www.rubydoc.info/github/test-unit/test-unit/Test/Unit) library.
+
+They require Ruby 2.7.0 or later.
+
+To run all tests from the repo root execute:
+
+```
+ruby test/integration/runner.rb
+```
+
+For a detailed guide on integration tests, see the documentation in the [integration test directory](./test/integration/).
+
+## Styleguides
+
+This project uses automatic code styling using [clang-format](https://clang.llvm.org/docs/ClangFormat.html) and [cmake-format](https://github.com/cheshirekow/cmake_format).
+The code style is enforced by the tools using the style options defined in the [.clang-format](./.clang-format) and [.cmake-format](./.cmake-format) configuration files.
+
+To install the necessary tools for code styling we recommend using recent version of [Python/pip](https://www.python.org).
+
+```bash
+pip3 install clang-format==14.0.6 cmake_format==0.6.11 pyyaml
+```
+
+For convenience, we have a CMake project defined in the [test/style](./test/style/) directory that can be called to automatically apply the code styling to all files currently added in git.
+
+```bash
+# initialize the project
+cmake -Stest/style -Bbuild/style
+# apply the code styling to this repository
+cmake --build build/style --target fix-format
+```
+
+<!-- omit in toc -->
+## Attribution
+This guide is based on the **contributing-gen**. [Make your own](https://github.com/bttger/contributing-gen)!

CONTRIBUTORS.md

@@ -0,0 +1,40 @@
+# CPM.cmake Contributors
+
+For detailed breakdown of individual contributions see the [Contributors page on GitHub](https://github.com/cpm-cmake/CPM.cmake/graphs/contributors)
+
+* [Lars Melchior](https://github.com/TheLartians)
+* [Borislav Stanimirov](https://github.com/iboB)
+* [Paul T](https://github.com/DeveloperPaul123)
+* [Leonardo Lima](https://github.com/leozz37)
+* [pgorgon-hem](https://github.com/pgorgon-hem)
+* [Xavier Muller](https://github.com/xmuller)
+* NVIDIA CORPORATION via [Robert Maynard](https://github.com/robertmaynard)
+* [Kingsley Chen](https://github.com/kingsamchen)
+* [alexandreSalconiDenis](https://github.com/alexandreSalconiDenis)
+* [DNKpp](https://github.com/DNKpp)
+* [Olivier Le Doeuff](https://github.com/OlivierLDff)
+* [Stuart Dootson](https://github.com/studoot)
+* [Tobias Hellmann](https://github.com/Tobi823)
+* [Giuseppe Cesarano](https://github.com/GiuseppeCesarano)
+* [Pavel Sokolov](https://github.com/hacker-cb)
+* [Claus Klein](https://github.com/ClausKlein)
+* [Clare Macrae](https://github.com/claremacrae)
+* [Kai Germaschewski](https://github.com/germasch)
+* [Andrea Barbadoro](https://github.com/andijcr)
+* [MixusMinimax](https://github.com/MixusMinimax)
+* [Dan Raviv](https://github.com/danra)
+* [Prabir Shrestha](https://github.com/prabirshrestha)
+* [Paul Taylor](https://github.com/trxcllnt)
+* [Ryan Mast](https://github.com/nightlark)
+* [Vinpasso](https://github.com/Vinpasso)
+* [Yotam Gingold](https://github.com/yig)
+* [jecassis](https://github.com/jecassis)
+* [Johel Ernesto Guerrero Peña](https://github.com/JohelEGP)
+* [Lars Bilke](https://github.com/bilke)
+* [Lava Block](https://github.com/TheLavaBlock)
+* [Anton Filimonov](https://github.com/variar)
+* [David Fong](https://github.com/david-fong)
+* [Thomas Mosegaard Pedersen](https://github.com/thomas-mp)
+* [Evgeny Gorodetskiy](https://github.com/egorodet)
+* [Kamil Kisiel](https://github.com/kisielk)
+* [AlessandroW](https://github.com/AlessandroW)

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2019 Lars Melchior
+Copyright (c) 2019-2022 Lars Melchior and contributors
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -1,7 +1,3 @@
-[![Build Status](https://travis-ci.com/cpm-cmake/CPM.cmake.svg?branch=master)](https://travis-ci.com/cpm-cmake/CPM.cmake)
-[![Actions Status](https://github.com/cpm-cmake/CPM.cmake/workflows/MacOS/badge.svg)](https://github.com/cpm-cmake/CPM.cmake/actions)
-[![Actions Status](https://github.com/cpm-cmake/CPM.cmake/workflows/Windows/badge.svg)](https://github.com/cpm-cmake/CPM.cmake/actions)
-[![Actions Status](https://github.com/cpm-cmake/CPM.cmake/workflows/Ubuntu/badge.svg)](https://github.com/cpm-cmake/CPM.cmake/actions)
 
 <br />
 <p align="center">
@@ -11,12 +7,12 @@
 
 # Setup-free CMake dependency management
 
-CPM.cmake is a CMake script that adds dependency management capabilities to CMake.
+CPM.cmake is a cross-platform CMake script that adds dependency management capabilities to CMake.
 It's built as a thin wrapper around CMake's [FetchContent](https://cmake.org/cmake/help/latest/module/FetchContent.html) module that adds version control, caching, a simple API [and more](#comparison-to-pure-fetchcontent--externalproject).
 
 ## Manage everything
 
-Any downloadable project or resource can be added as a version-controlled dependency though CPM, it is not necessary to modify or package anything.
+Any downloadable project or resource can be added as a version-controlled dependency through CPM, it is not necessary to modify or package anything.
 Projects using modern CMake are automatically configured and their targets can be used immediately.
 For everything else, the targets can be created manually after the dependency has been downloaded (see the [snippets](#snippets) below for examples).
 
@@ -25,63 +21,6 @@ For everything else, the targets can be created manually after the dependency ha
 - [CPM: An Awesome Dependency Manager for C++ with CMake](https://medium.com/swlh/cpm-an-awesome-dependency-manager-for-c-with-cmake-3c53f4376766)
 - [CMake and the Future of C++ Package Management](https://ibob.github.io/blog/2020/01/13/cmake-package-management/)
 
-## Usage
-
-After `CPM.cmake` has been [added](#adding-cpm) to your project, the function `CPMAddPackage` can be used to fetch and configure a dependency.
-Afterwards, any targets defined in the dependency can be used directly.
-`CPMAddPackage` takes the following named parameters.
-
-```cmake
-CPMAddPackage(
-  NAME          # The unique name of the dependency (should be the exported target's name)
-  VERSION       # The minimum version of the dependency (optional, defaults to 0)
-  OPTIONS       # Configuration options passed to the dependency (optional)
-  DOWNLOAD_ONLY # If set, the project is downloaded, but not configured (optional)
-  [...]         # Origin parameters forwarded to FetchContent_Declare, see below
-)
-```
-
-The origin may be specified by a `GIT_REPOSITORY`, but other sources, such as direct URLs, are [also supported](https://cmake.org/cmake/help/v3.11/module/ExternalProject.html#external-project-definition).
-If `GIT_TAG` hasn't been explicitly specified it defaults to `v(VERSION)`, a common convention for git projects.
-On the other hand, if `VERSION` hasn't been explicitly specified, CPM can automatically identify the version from the git tag in some common cases.
-`GIT_TAG` can also be set to a specific commit or a branch name such as `master`, however this isn't recommended, as such packages will only be updated when the cache is cleared.
-
-If an additional optional parameter `EXCLUDE_FROM_ALL` is set to a truthy value, then any targets defined inside the dependency won't be built by default. See the [CMake docs](https://cmake.org/cmake/help/latest/prop_tgt/EXCLUDE_FROM_ALL.html) for details.
-
-A single-argument compact syntax is also supported:
-
-```cmake
-# A git package from a given uri with a version
-CPMAddPackage("uri@version")
-# A git package from a given uri with a git tag or commit hash
-CPMAddPackage("uri#tag")
-# A git package with both version and tag provided
-CPMAddPackage("uri@version#tag")
-```
-
-In the shorthand syntax if the URI is of the form `gh:user/name`, it is interpreted as GitHub URI and converted to `https://github.com/user/name.git`. If the URI is of the form `gl:user/name`, it is interpreted as a [GitLab](https://gitlab.com/explore/) URI and converted to `https://gitlab.com/user/name.git`. If the URI is of the form `bb:user/name`, it is interpreted as a [Bitbucket](https://bitbucket.org/) URI and converted to `https://bitbucket.org/user/name.git`. Otherwise the URI used verbatim as a git URL. All packages added using the shorthand syntax will be added using the [EXCLUDE_FROM_ALL](https://cmake.org/cmake/help/latest/prop_tgt/EXCLUDE_FROM_ALL.html) flag.
-
-The single-argument syntax also works for URLs:
-
-```cmake
-# An archive package from a given url. The version is inferred
-CPMAddPackage("https://example.com/my-package-1.2.3.zip")
-# An archive package from a given url with an MD5 hash provided
-CPMAddPackage("https://example.com/my-package-1.2.3.zip#MD5=68e20f674a48be38d60e129f600faf7d")
-# An archive package from a given url. The version is explicitly given
-CPMAddPackage("https://example.com/my-package.zip@1.2.3")
-```
-
-After calling `CPMAddPackage`, the following variables are defined in the local scope, where `<dependency>` is the name of the dependency.
-
-- `<dependency>_SOURCE_DIR` is the path to the source of the dependency.
-- `<dependency>_BINARY_DIR` is the path to the build directory of the dependency.
-- `<dependency>_ADDED` is set to `YES` if the dependency has not been added before, otherwise it is set to `NO`.
-
-For using CPM.cmake projects with external package managers, such as conan or vcpkg, setting the variable [`CPM_USE_LOCAL_PACKAGES`](#options) will make CPM.cmake try to add a package through `find_package` first, and add it from source if it doesn't succeed.
-
-In rare cases, this behaviour may be desirable by default. The function `CPMFindPackage` will try to find a local dependency via CMake's `find_package` and fallback to `CPMAddPackage`, if the dependency is not found.
-
 ## Full CMakeLists Example
 
 ```cmake
@@ -91,14 +30,17 @@ cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
 project(MyProject)
 
 # add executable
-add_executable(tests tests.cpp)
+add_executable(main main.cpp)
 
 # add dependencies
 include(cmake/CPM.cmake)
-CPMAddPackage("gh:catchorg/Catch2@2.5.0")
+
+CPMAddPackage("gh:fmtlib/fmt#7.1.3")
+CPMAddPackage("gh:nlohmann/json@3.10.5")
+CPMAddPackage("gh:catchorg/Catch2@3.4.0")
 
 # link dependencies
-target_link_libraries(tests Catch2)
+target_link_libraries(main fmt::fmt nlohmann_json::nlohmann_json Catch2::Catch2WithMain)
 ```
 
 See the [examples directory](https://github.com/cpm-cmake/CPM.cmake/tree/master/examples) for complete examples with source code and check [below](#snippets) or in the [wiki](https://github.com/cpm-cmake/CPM.cmake/wiki/More-Snippets) for example snippets.
@@ -115,9 +57,88 @@ wget -O cmake/CPM.cmake https://github.com/cpm-cmake/CPM.cmake/releases/latest/d
 
 You can also download CPM.cmake directly from your project's `CMakeLists.txt`. See the [wiki](https://github.com/cpm-cmake/CPM.cmake/wiki/Downloading-CPM.cmake-in-CMake) for more details.
 
+## Usage
+
+After `CPM.cmake` has been [added](#adding-cpm) to your project, the function `CPMAddPackage` can be used to fetch and configure a dependency.
+Afterwards, any targets defined in the dependency can be used directly.
+`CPMAddPackage` takes the following named parameters.
+
+```cmake
+CPMAddPackage(
+  NAME          # The unique name of the dependency (should be the exported target's name)
+  VERSION       # The minimum version of the dependency (optional, defaults to 0)
+  PATCHES       # Patch files to be applied sequentially using patch and PATCH_OPTIONS (optional)
+  OPTIONS       # Configuration options passed to the dependency (optional)
+  DOWNLOAD_ONLY # If set, the project is downloaded, but not configured (optional)
+  [...]         # Origin parameters forwarded to FetchContent_Declare, see below
+)
+```
+
+The origin may be specified by a `GIT_REPOSITORY`, but other sources, such as direct URLs, are [also supported](https://cmake.org/cmake/help/v3.11/module/ExternalProject.html#external-project-definition).
+If `GIT_TAG` hasn't been explicitly specified it defaults to `v(VERSION)`, a common convention for git projects.
+On the other hand, if `VERSION` hasn't been explicitly specified, CPM can automatically identify the version from the git tag in some common cases.
+`GIT_TAG` can also be set to a specific commit or a branch name such as `master`, however this isn't recommended, as such packages will only be updated when the cache is cleared.
+
+`PATCHES` takes a list of patch files to apply sequentially. For a basic example, see [Highway](examples/highway/CMakeLists.txt).
+We recommend that if you use `PATCHES`, you also set `CPM_SOURCE_CACHE`. See [issue 577](https://github.com/cpm-cmake/CPM.cmake/issues/577).
+
+If an additional optional parameter `EXCLUDE_FROM_ALL` is set to a truthy value, then any targets defined inside the dependency won't be built by default. See the [CMake docs](https://cmake.org/cmake/help/latest/prop_tgt/EXCLUDE_FROM_ALL.html) for details.
+
+If an additional optional parameter `SYSTEM` is set to a truthy value, the SYSTEM directory property of the subdirectory added will be set to true.
+See the [add_subdirectory ](https://cmake.org/cmake/help/latest/command/add_subdirectory.html?highlight=add_subdirectory)
+and [SYSTEM](https://cmake.org/cmake/help/latest/prop_tgt/SYSTEM.html#prop_tgt:SYSTEM) target property for details.
+
+A shorthand syntax is also supported:
+
+```cmake
+# A git package from a given uri with a version
+CPMAddPackage("uri@version")
+# A git package from a given uri with a git tag or commit hash
+CPMAddPackage("uri#tag")
+# A git package with both version and tag provided
+CPMAddPackage("uri@version#tag")
+```
+
+In the shorthand syntax if the URI is of the form `gh:user/name`, it is interpreted as GitHub URI and converted to `https://github.com/user/name.git`. If the URI is of the form `gl:user/name`, it is interpreted as a [GitLab](https://gitlab.com/explore/) URI and converted to `https://gitlab.com/user/name.git`. If the URI is of the form `bb:user/name`, it is interpreted as a [Bitbucket](https://bitbucket.org/) URI and converted to `https://bitbucket.org/user/name.git`. Otherwise the URI used verbatim as a git URL. All packages added using the shorthand syntax will be added using the [EXCLUDE_FROM_ALL](https://cmake.org/cmake/help/latest/prop_tgt/EXCLUDE_FROM_ALL.html) and [SYSTEM](https://cmake.org/cmake/help/latest/prop_tgt/SYSTEM.html#prop_tgt:SYSTEM) flag.
+
+The single-argument syntax also works for URLs:
+
+```cmake
+# An archive package from a given url. The version is inferred
+CPMAddPackage("https://example.com/my-package-1.2.3.zip")
+# An archive package from a given url with an MD5 hash provided
+CPMAddPackage("https://example.com/my-package-1.2.3.zip#MD5=68e20f674a48be38d60e129f600faf7d")
+# An archive package from a given url. The version is explicitly given
+CPMAddPackage("https://example.com/my-package.zip@1.2.3")
+```
+
+Additionally, if needed, extra arguments can be provided while using single argument syntax by using the shorthand syntax with the `URI` specifier.
+
+```cmake
+CPMAddPackage(
+  URI "gh:nlohmann/json@3.9.1"
+  OPTIONS "JSON_BuildTests OFF"
+)
+```
+
+The `URI` argument must be the first argument to `CPMAddPackage`.
+`URI` automatically sets `EXCLUDE_FROM_ALL YES` and `SYSTEM YES`.
+If this is not desired, `EXCLUDE_FROM_ALL NO` and `SYSTEM NO` can be set afterwards.
+
+After calling `CPMAddPackage`, the following variables are defined in the local scope, where `<dependency>` is the name of the dependency.
+
+- `<dependency>_SOURCE_DIR` is the path to the source of the dependency.
+- `<dependency>_BINARY_DIR` is the path to the build directory of the dependency.
+- `<dependency>_ADDED` is set to `YES` if the dependency has not been added before, otherwise it is set to `NO`.
+- `CPM_LAST_PACKAGE_NAME` is set to the determined name of the last added dependency (equivalent to `<dependency>`).
+
+For using CPM.cmake projects with external package managers, such as conan or vcpkg, setting the variable [`CPM_USE_LOCAL_PACKAGES`](#options) will make CPM.cmake try to add a package through `find_package` first, and add it from source if it doesn't succeed.
+
+In rare cases, this behaviour may be desirable by default. The function `CPMFindPackage` will try to find a local dependency via CMake's `find_package` and fallback to `CPMAddPackage`, if the dependency is not found.
+
 ## Updating CPM
 
-To update CPM to the newest version, update the script in the project's root directory, for example by running the command above.
+To update CPM to the newest version, update the script in the project's root directory, for example by running the same command as for [adding CPM](#adding-cpm).
 Dependencies using CPM will automatically use the updated script of the outermost project.
 
 ## Advantages
@@ -135,6 +156,10 @@ Dependencies using CPM will automatically use the updated script of the outermos
 - **No pre-built binaries** For every new build directory, all dependencies are initially downloaded and built from scratch. To avoid extra downloads it is recommend to set the [`CPM_SOURCE_CACHE`](#CPM_SOURCE_CACHE) environmental variable. Using a caching compiler such as [ccache](https://github.com/TheLartians/Ccache.cmake) can drastically reduce build time.
 - **Dependent on good CMakeLists** Many libraries do not have CMakeLists that work well for subprojects. Luckily this is slowly changing, however, until then, some manual configuration may be required (see the snippets [below](#snippets) for examples). For best practices on preparing projects for CPM, see the [wiki](https://github.com/cpm-cmake/CPM.cmake/wiki/Preparing-projects-for-CPM.cmake).
 - **First version used** In diamond-shaped dependency graphs (e.g. `A` depends on `C`@1.1 and `B`, which itself depends on `C`@1.2 the first added dependency will be used (in this case `C`@1.1). In this case, B requires a newer version of `C` than `A`, so CPM will emit a warning. This can be easily resolved by adding a new version of the dependency in the outermost project, or by introducing a [package lock file](#package-lock).
+- **Some CMake policies set to `NEW`** Including CPM.cmake will lead to several CMake policies being set to `NEW`. Users which need the old behavior will need to manually modify their CMake code to ensure they're set to `OLD` at the appropriate places. The policies are:
+    - [CMP0077](https://cmake.org/cmake/help/latest/policy/CMP0077.html) and [CMP0126](https://cmake.org/cmake/help/latest/policy/CMP0126.html). They make setting package options from `CMPAddPackage` possible.
+    - [CMP0135](https://cmake.org/cmake/help/latest/policy/CMP0135.html) It allows for proper package rebuilds of packages which are archives, source cache is not used, and the package URL is changed to an older version.
+    - [CMP0150](https://cmake.org/cmake/help/latest/policy/CMP0150.html) Relative paths provided to `GIT_REPOSITORY` are treated as relative to the parent project's remote.
 
 For projects with more complex needs and where an extra setup step doesn't matter, it may be worth to check out an external C++ package manager such as [vcpkg](https://github.com/microsoft/vcpkg), [conan](https://conan.io) or [hunter](https://github.com/ruslo/hunter).
 Dependencies added with `CPMFindPackage` should work with external package managers.
@@ -182,20 +207,39 @@ Note that passing the variable as a configure option to CMake will always overri
 
 You can use `CPM_SOURCE_CACHE` on GitHub Actions workflows [cache](https://github.com/actions/cache) and combine it with ccache, to make your CI faster. See the [wiki](https://github.com/cpm-cmake/CPM.cmake/wiki/Caching-with-CPM.cmake-and-ccache-on-GitHub-Actions) for more info.
 
+The directory where the version for a project is stored is by default the hash of the arguments to `CPMAddPackage()`.
+If for instance the patch command uses external files, the directory name can be set with the argument `CUSTOM_CACHE_KEY`.
+
 ### CPM_DOWNLOAD_ALL
 
 If set, CPM will forward all calls to `CPMFindPackage` as `CPMAddPackage`.
 This is useful to create reproducible builds or to determine if the source parameters have all been set correctly.
 This can also be set as an environmental variable.
+This can be controlled on a per package basis with the `CPM_DOWNLOAD_<dependency name>` variable.
 
 ### CPM_USE_LOCAL_PACKAGES
 
 CPM can be configured to use `find_package` to search for locally installed dependencies first by setting the CMake option `CPM_USE_LOCAL_PACKAGES`.
+
 If the option `CPM_LOCAL_PACKAGES_ONLY` is set, CPM will emit an error if the dependency is not found locally.
 These options can also be set as environmental variables.
 
 In the case that `find_package` requires additional arguments, the parameter `FIND_PACKAGE_ARGUMENTS` may be specified in the `CPMAddPackage` call. The value of this parameter will be forwarded to `find_package`.
 
+Note that this does not apply to dependencies that have been defined with a truthy `FORCE` parameter. These will be added as defined.
+
+### CPM_DONT_UPDATE_MODULE_PATH
+
+By default, CPM will override any `find_package` commands to use the CPM downloaded version.
+This is equivalent to the `OVERRIDE_FIND_PACKAGE` FetchContent option, which has no effect in CPM.
+To disable this behaviour set the `CPM_DONT_UPDATE_MODULE_PATH` option.
+This will not work for `find_package(CONFIG)` in CMake versions before 3.24.
+
+### CPM_USE_NAMED_CACHE_DIRECTORIES
+
+If set, CPM use additional directory level in cache to improve readability of packages names in IDEs like CLion. It changes cache structure, so all dependencies are downloaded again. There is no problem to mix both structures in one cache directory but then there may be 2 copies of some dependencies.
+This can also be set as an environmental variable.
+
 ## Local package override
 
 Library developers are often in the situation where they work on a locally checked out dependency at the same time as on a consumer project.
@@ -225,6 +269,22 @@ cmake --build build --target cpm-update-package-lock
 
 See the [wiki](https://github.com/cpm-cmake/CPM.cmake/wiki/Package-lock) for more info.
 
+## Private repositories and CI
+
+When using CPM.cmake with private repositories, there may be a need to provide an [access token](https://docs.github.com/en/authentication/keeping-your-account-and-data-secure/creating-a-personal-access-token) to be able to clone other projects. Instead of providing the token in CMake, we recommend to provide the regular URL and use [git-config](https://git-scm.com/docs/git-config) to rewrite the URLs to include the token.
+
+As an example, you could include one of the following in your CI script.
+
+```bash
+# Github
+git config --global url."https://${USERNAME}:${TOKEN}@github.com".insteadOf "https://github.com"
+```
+
+```bash
+# GitLab
+git config --global url."https://gitlab-ci-token:${CI_JOB_TOKEN}@gitlab.com".insteadOf "https://gitlab.com"
+```
+
 ## Built with CPM.cmake
 
 Some amazing projects that are built using the CPM.cmake package manager.
@@ -257,6 +317,84 @@ If you know others, feel free to add them here through a PR.
       </a>
     </td>
   </tr>
+  <tr>
+    <td>
+      <a href="https://git.io/liblava">
+        <p align="center">
+          <img src="https://github.com/liblava.png" alt="liblava" width="100pt" />
+        </p>
+        <p align="center"><b>liblava - Modern Vulkan library</b></p>
+      </a>
+    </td>
+    <td>
+      <a href="https://github.com/variar/klogg">
+        <p align="center">
+          <img src="https://github.com/variar/klogg/blob/master/src/app/images/hicolor/scalable/klogg.svg" alt="klogg" width="100pt" />
+        </p>
+        <p align="center"><b>klogg - fast advanced log explorer</b></p>
+      </a>
+    </td>
+    <td>
+      <a href="https://github.com/MethanePowered/MethaneKit">
+        <p align="center">
+          <img src="https://github.com/MethanePowered/MethaneKit/raw/master/Docs/Images/Logo/MethaneLogoSmall.png" alt="MethaneKit" width="100pt" />
+        </p>
+        <p align="center"><b>Methane Kit - modern 3D graphics rendering framework</b></p>
+      </a>
+    </td>
+  </tr>
+  <tr>
+    <td>
+      <a href="https://github.com/jhasse/jngl">
+        <p align="center">
+          <img src="https://github.com/jhasse/jngl/raw/master/doc/jngl-logo.svg" alt="JNGL" width="100pt" />
+        </p>
+        <p align="center"><b>JNGL - easy to use cross-platform 2D game library</b></p>
+      </a>
+    </td>
+    <td>
+      <a href="https://github.com/sillydan1/aaltitoad">
+        <p align="center">
+          <img src="https://github.com/sillydan1/aaltitoad/raw/v1.1.0/.github/resources/logo/toad_only.svg" alt="aaltitoad" width="100pt" />
+        </p>
+        <p align="center"><b>AALTITOAD - verifier and simulator for Tick Tock Automata</b></p>
+      </a>
+    </td>
+    <td>
+      <a href="https://github.com/ZIMO-Elektronik">
+        <p align="center">
+          <img src="https://avatars.githubusercontent.com/u/117935012?s=400&u=9a871a46dd13437f0adcae166e9efbe518ff0b99&v=4" alt="ZIMO-Elektronik" width="100pt" />
+        </p>
+        <p align="center"><b>ZIMO-Elektronik</b></p>
+      </a>
+    </td>
+  </tr>
+  <tr>
+    <td>
+      <a href="https://github.com/ada-url/ada">
+        <p align="center">
+          <img src="https://avatars.githubusercontent.com/u/120840559?s=200&v=4" alt="ada" width="100pt" />
+        </p>
+        <p align="center"><b>ada - WHATWG-compliant and fast URL parser written in modern C++</b></p>
+      </a>
+    </td>
+    <td>
+      <a href="https://github.com/exaloop/codon">
+        <p align="center">
+          <img src="https://github.com/exaloop/codon/blob/develop/docs/img/logo.png?raw=true" alt="codon" width="100pt" />
+        </p>
+        <p align="center"><b>codon - A high-performance, zero-overhead, extensible Python compiler using LLVM</b></p>
+      </a>
+    </td>
+    <td>
+      <a href="https://github.com/RoaringBitmap/CRoaring">
+        <p align="center">
+          <img src="https://avatars.githubusercontent.com/u/16548876?s=200&v=4" alt="CRoaring" width="100pt" />
+        </p>
+        <p align="center"><b>CRoaring - Roaring bitmaps in C (and C++), with SIMD (AVX2, AVX-512 and NEON) optimizations: used by Apache Doris, ClickHouse, and StarRocks</b></p>
+      </a>
+    </td>
+  </tr>
 </table>
 
 ## Snippets
@@ -270,11 +408,10 @@ See the [wiki](https://github.com/cpm-cmake/CPM.cmake/wiki/More-Snippets) for mo
 CPMAddPackage("gh:catchorg/Catch2@2.5.0")
 ```
 
-### [Boost (via boost-cmake)](https://github.com/Orphis/boost-cmake)
+### [Range-v3](https://github.com/ericniebler/range-v3)
 
-```CMake
+```Cmake
-# boost-cmake currently doesn't tag versions, so we use the according boost version
+CPMAddPackage("gh:ericniebler/range-v3#0.12.0")
-CPMAddPackage("gh:Orphis/boost-cmake#7f97a08b64bd5d2e53e932ddf80c40544cf45edf@1.71.0")
 ```
 
 ### [Yaml-cpp](https://github.com/jbeder/yaml-cpp)
@@ -284,30 +421,42 @@ CPMAddPackage("gh:Orphis/boost-cmake#7f97a08b64bd5d2e53e932ddf80c40544cf45edf@1.
 CPMAddPackage("gh:jbeder/yaml-cpp#yaml-cpp-0.6.3@0.6.3")
 ```
 
-### [Range-v3](https://github.com/ericniebler/range-v3)
-
-```Cmake
-CPMAddPackage("gh:ericniebler/range-v3#0.11.0")
-```
-
 ### [nlohmann/json](https://github.com/nlohmann/json)
 
 ```cmake
 CPMAddPackage(
-  NAME nlohmann_json
+  URI "gh:nlohmann/json@3.9.1"
-  VERSION 3.9.1
+  OPTIONS "JSON_BuildTests OFF"
-  OPTIONS 
-    "JSON_BuildTests OFF"
 )
 ```
 
+### [Boost](https://github.com/boostorg/boost)
+
+Boost is a large project and will take a while to download. Using
+`CPM_SOURCE_CACHE` is strongly recommended. Cloning moves much more
+data than a source archive, so this sample will use a compressed
+source archive (tar.xz) release from Boost's github page.
+
+```CMake
+# boost is a huge project and directly downloading the 'alternate release'
+# from github is much faster than recursively cloning the repo.
+CPMAddPackage(
+  NAME Boost
+  VERSION 1.84.0
+  URL https://github.com/boostorg/boost/releases/download/boost-1.84.0/boost-1.84.0.tar.xz
+  URL_HASH SHA256=2e64e5d79a738d0fa6fb546c6e5c2bd28f88d268a2a080546f74e5ff98f29d0e
+  OPTIONS "BOOST_ENABLE_CMAKE ON"
+)
+```
+
+For a working example of using CPM to download and configure the Boost C++ Libraries see [here](examples/boost).
+
 ### [cxxopts](https://github.com/jarro2783/cxxopts)
 
 ```cmake
 # the install option has to be explicitly set to allow installation
 CPMAddPackage(
-  GITHUB_REPOSITORY jarro2783/cxxopts
+  URI "gh:jarro2783/cxxopts@2.2.1"
-  VERSION 2.2.1
   OPTIONS "CXXOPTS_BUILD_EXAMPLES NO" "CXXOPTS_BUILD_TESTS NO" "CXXOPTS_ENABLE_INSTALL YES"
 )
 ```
@@ -316,9 +465,7 @@ CPMAddPackage(
 
 ```cmake
 CPMAddPackage(
-  NAME benchmark
+  URI "gh:google/benchmark@1.5.2"
-  GITHUB_REPOSITORY google/benchmark
-  VERSION 1.5.2
   OPTIONS "BENCHMARK_ENABLE_TESTING Off"
 )
 
@@ -357,3 +504,85 @@ For a full example on using CPM to download and configure lua with sol2 see [her
 ### Full Examples
 
 See the [examples directory](https://github.com/cpm-cmake/CPM.cmake/tree/master/examples) for full examples with source code and check out the [wiki](https://github.com/cpm-cmake/CPM.cmake/wiki/More-Snippets) for many more example snippets.
+
+## Source Archives from GitHub
+
+Using a compressed source archive is usually much faster than a shallow
+clone. Optionally, you can verify the integrity using
+[SHA256](https://en.wikipedia.org/wiki/SHA-2) or similar. Setting the hash is useful to ensure a
+specific source is imported, especially since tags, branches, and
+archives can change.
+
+Let's look at adding [spdlog](https://github.com/gabime/spdlog) to a project:
+
+```cmake
+CPMAddPackage(
+  NAME     spdlog
+  URL      https://github.com/gabime/spdlog/archive/refs/tags/v1.12.0.zip
+  URL_HASH SHA256=6174bf8885287422a6c6a0312eb8a30e8d22bcfcee7c48a6d02d1835d7769232
+)
+```
+
+URL_HASH is optional, but it's a good idea for releases.
+
+
+### Identifying the URL
+
+Information for determining the URL is found
+[here](https://docs.github.com/en/repositories/working-with-files/using-files/downloading-source-code-archives#source-code-archive-urls).
+
+
+#### Release
+
+Not every software package provides releases, but for those that do,
+they can be found on the release page of the project. In a browser,
+the URL of the specific release is determined in a browser is
+determined by right clicking and selecting `Copy link address` (or
+similar) for the desired release. This is the value you will use in
+the URL section.
+
+This is the URL for spdlog release 1.13.0 in zip format:
+`https://github.com/gabime/spdlog/archive/refs/tags/v1.13.0.zip`
+
+
+#### Branch
+
+The URL for branches is non-obvious from a browser. But it's still fairly easy to figure it out. The format is as follows:
+
+`https://github.com/<user>/<name>/archive/refs/heads/<branch-name>.<archive-type>`
+
+Archive type can be one of `tar.gz` or `zip`.
+
+The URL for branch `v2.x` of spdlog is:
+`https://github.com/gabime/spdlog/archive/refs/heads/v2.x.tar.gz`
+
+
+#### Tag
+
+Tags are similar, but with this format:
+
+`https://github.com/<user>/<name>/archive/refs/tags/<tag-name>.<archive-type>`
+
+Tag `v1.8.5` of spdlog is this:
+
+`https://github.com/gabime/spdlog/archive/refs/tags/v1.8.5.tar.gz`
+
+Exactly like the release.
+
+
+#### Commit
+
+If a specific commit contains the code you need, it's defined as follows:
+
+`https://github.com/<user>/<name>/archive/<commit-hash>.<archive-type>`
+
+Example:
+`https://github.com/gabime/spdlog/archive/c1569a3d293a6b511ecb9c18b2298826c9578d9f.tar.gz`
+
+
+### Determining the Hash
+
+The following snippet illustrates determining the SHA256 hash on a linux machine using `wget` and `sha256sum`:
+```bash
+wget https://github.com/gabime/spdlog/archive/refs/tags/v1.13.0.zip -O - | sha256sum
+```

cmake/.cmake-format-additional_commands-cpm

@@ -0,0 +1,75 @@
+parse:
+  additional_commands:
+    cpmaddpackage:
+      pargs:
+        nargs: '*'
+        flags: []
+      spelling: CPMAddPackage
+      kwargs: &cpmaddpackagekwargs
+        NAME: 1
+        FORCE: 1
+        VERSION: 1
+        GIT_TAG: 1
+        DOWNLOAD_ONLY: 1
+        GITHUB_REPOSITORY: 1
+        GITLAB_REPOSITORY: 1
+        GIT_REPOSITORY: 1
+        SVN_REPOSITORY: 1
+        SVN_REVISION: 1
+        SOURCE_DIR: 1
+        DOWNLOAD_COMMAND: 1
+        FIND_PACKAGE_ARGUMENTS: 1
+        NO_CACHE: 1
+        GIT_SHALLOW: 1
+        URL: 1
+        URL_HASH: 1
+        URL_MD5: 1
+        DOWNLOAD_NAME: 1
+        DOWNLOAD_NO_EXTRACT: 1
+        HTTP_USERNAME: 1
+        HTTP_PASSWORD: 1
+        EXCLUDE_FROM_ALL: 1
+        SYSTEM: 1
+        SOURCE_SUBDIR: 1
+        PATCHES: +
+        OPTIONS: +
+    cpmfindpackage:
+      pargs:
+        nargs: '*'
+        flags: []
+      spelling: CPMFindPackage
+      kwargs: *cpmaddpackagekwargs
+    cpmdeclarepackage:
+      pargs:
+        nargs: '*'
+        flags: []
+      spelling: CPMDeclarePackage
+      kwargs: *cpmaddpackagekwargs
+    packageproject:
+      pargs:
+        nargs: '*'
+        flags: []
+      spelling: packageProject
+      kwargs:
+        NAME: 1
+        VERSION: 1
+        NAMESPACE: 1
+        INCLUDE_DIR: 1
+        INCLUDE_DESTINATION: 1
+        INCLUDE_HEADER_PATTERN: 1
+        BINARY_DIR: 1
+        COMPATIBILITY: 1
+        VERSION_HEADER: 1
+        EXPORT_HEADER: 1
+        DISABLE_VERSION_SUFFIX: 1
+        CPACK: 1
+        DEPENDENCIES: +
+    cpmusepackagelock:
+      pargs: 1
+      spelling: CPMUsePackageLock
+    cpmregisterpackage:
+      pargs: 1
+      spelling: CPMRegisterPackage
+    cpmgetpackageversion:
+      pargs: 2
+      spelling: CPMGetPackageVersion

cmake/CPM.cmake

@@ -5,7 +5,7 @@
 # MIT License
 # -----------
 #[[
-  Copyright (c) 2021 Lars Melchior and additional contributors
+  Copyright (c) 2019-2023 Lars Melchior and contributors
 
   Permission is hereby granted, free of charge, to any person obtaining a copy
   of this software and associated documentation files (the "Software"), to deal
@@ -28,10 +28,29 @@
 
 cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
 
-set(CURRENT_CPM_VERSION 1.0.0-development-version)
+# Initialize logging prefix
+if(NOT CPM_INDENT)
+  set(CPM_INDENT
+      "CPM:"
+      CACHE INTERNAL ""
+  )
+endif()
 
+if(NOT COMMAND cpm_message)
+  function(cpm_message)
+    message(${ARGV})
+  endfunction()
+endif()
+
+if(DEFINED EXTRACTED_CPM_VERSION)
+  set(CURRENT_CPM_VERSION "${EXTRACTED_CPM_VERSION}${CPM_DEVELOPMENT}")
+else()
+  set(CURRENT_CPM_VERSION 1.0.0-development-version)
+endif()
+
+get_filename_component(CPM_CURRENT_DIRECTORY "${CMAKE_CURRENT_LIST_DIR}" REALPATH)
 if(CPM_DIRECTORY)
-  if(NOT CPM_DIRECTORY STREQUAL CMAKE_CURRENT_LIST_DIR)
+  if(NOT CPM_DIRECTORY STREQUAL CPM_CURRENT_DIRECTORY)
     if(CPM_VERSION VERSION_LESS CURRENT_CPM_VERSION)
       message(
         AUTHOR_WARNING
@@ -57,8 +76,42 @@ See https://github.com/cpm-cmake/CPM.cmake for more information."
   endif()
 endif()
 
+if(CURRENT_CPM_VERSION MATCHES "development-version")
+  message(
+    WARNING "${CPM_INDENT} Your project is using an unstable development version of CPM.cmake. \
+Please update to a recent release if possible. \
+See https://github.com/cpm-cmake/CPM.cmake for details."
+  )
+endif()
+
 set_property(GLOBAL PROPERTY CPM_INITIALIZED true)
 
+macro(cpm_set_policies)
+  # the policy allows us to change options without caching
+  cmake_policy(SET CMP0077 NEW)
+  set(CMAKE_POLICY_DEFAULT_CMP0077 NEW)
+
+  # the policy allows us to change set(CACHE) without caching
+  if(POLICY CMP0126)
+    cmake_policy(SET CMP0126 NEW)
+    set(CMAKE_POLICY_DEFAULT_CMP0126 NEW)
+  endif()
+
+  # The policy uses the download time for timestamp, instead of the timestamp in the archive. This
+  # allows for proper rebuilds when a projects url changes
+  if(POLICY CMP0135)
+    cmake_policy(SET CMP0135 NEW)
+    set(CMAKE_POLICY_DEFAULT_CMP0135 NEW)
+  endif()
+
+  # treat relative git repository paths as being relative to the parent project's remote
+  if(POLICY CMP0150)
+    cmake_policy(SET CMP0150 NEW)
+    set(CMAKE_POLICY_DEFAULT_CMP0150 NEW)
+  endif()
+endmacro()
+cpm_set_policies()
+
 option(CPM_USE_LOCAL_PACKAGES "Always try to use `find_package` to get dependencies"
        $ENV{CPM_USE_LOCAL_PACKAGES}
 )
@@ -76,13 +129,17 @@ option(CPM_INCLUDE_ALL_IN_PACKAGE_LOCK
        "Add all packages added through CPM.cmake to the package lock"
        $ENV{CPM_INCLUDE_ALL_IN_PACKAGE_LOCK}
 )
+option(CPM_USE_NAMED_CACHE_DIRECTORIES
+       "Use additional directory of package name in cache on the most nested level."
+       $ENV{CPM_USE_NAMED_CACHE_DIRECTORIES}
+)
 
 set(CPM_VERSION
     ${CURRENT_CPM_VERSION}
     CACHE INTERNAL ""
 )
 set(CPM_DIRECTORY
-    ${CMAKE_CURRENT_LIST_DIR}
+    ${CPM_CURRENT_DIRECTORY}
     CACHE INTERNAL ""
 )
 set(CPM_FILE
@@ -109,7 +166,7 @@ set(CPM_SOURCE_CACHE
     CACHE PATH "Directory to download CPM dependencies"
 )
 
-if(NOT CPM_DONT_UPDATE_MODULE_PATH)
+if(NOT CPM_DONT_UPDATE_MODULE_PATH AND NOT DEFINED CMAKE_FIND_PACKAGE_REDIRECTS_DIR)
   set(CPM_MODULE_PATH
       "${CMAKE_BINARY_DIR}/CPM_modules"
       CACHE INTERNAL ""
@@ -145,6 +202,60 @@ function(cpm_package_name_from_git_uri URI RESULT)
   endif()
 endfunction()
 
+# Find the shortest hash that can be used eg, if origin_hash is
+# cccb77ae9609d2768ed80dd42cec54f77b1f1455 the following files will be checked, until one is found
+# that is either empty (allowing us to assign origin_hash), or whose contents matches ${origin_hash}
+#
+# * .../cccb.hash
+# * .../cccb77ae.hash
+# * .../cccb77ae9609.hash
+# * .../cccb77ae9609d276.hash
+# * etc
+#
+# We will be able to use a shorter path with very high probability, but in the (rare) event that the
+# first couple characters collide, we will check longer and longer substrings.
+function(cpm_get_shortest_hash source_cache_dir origin_hash short_hash_output_var)
+  # for compatibility with caches populated by a previous version of CPM, check if a directory using
+  # the full hash already exists
+  if(EXISTS "${source_cache_dir}/${origin_hash}")
+    set(${short_hash_output_var}
+        "${origin_hash}"
+        PARENT_SCOPE
+    )
+    return()
+  endif()
+
+  foreach(len RANGE 4 40 4)
+    string(SUBSTRING "${origin_hash}" 0 ${len} short_hash)
+    set(hash_lock ${source_cache_dir}/${short_hash}.lock)
+    set(hash_fp ${source_cache_dir}/${short_hash}.hash)
+    # Take a lock, so we don't have a race condition with another instance of cmake. We will release
+    # this lock when we can, however, if there is an error, we want to ensure it gets released on
+    # it's own on exit from the function.
+    file(LOCK ${hash_lock} GUARD FUNCTION)
+
+    # Load the contents of .../${short_hash}.hash
+    file(TOUCH ${hash_fp})
+    file(READ ${hash_fp} hash_fp_contents)
+
+    if(hash_fp_contents STREQUAL "")
+      # Write the origin hash
+      file(WRITE ${hash_fp} ${origin_hash})
+      file(LOCK ${hash_lock} RELEASE)
+      break()
+    elseif(hash_fp_contents STREQUAL origin_hash)
+      file(LOCK ${hash_lock} RELEASE)
+      break()
+    else()
+      file(LOCK ${hash_lock} RELEASE)
+    endif()
+  endforeach()
+  set(${short_hash_output_var}
+      "${short_hash}"
+      PARENT_SCOPE
+  )
+endfunction()
+
 # Try to infer package name and version from a url
 function(cpm_package_name_and_ver_from_url url outName outVer)
   if(url MATCHES "[/\\?]([a-zA-Z0-9_\\.-]+)\\.(tar|tar\\.gz|tar\\.bz2|zip|ZIP)(\\?|/|$)")
@@ -191,19 +302,14 @@ function(cpm_package_name_and_ver_from_url url outName outVer)
   endif()
 endfunction()
 
-# Initialize logging prefix
-if(NOT CPM_INDENT)
-  set(CPM_INDENT
-      "CPM:"
-      CACHE INTERNAL ""
-  )
-endif()
-
 function(cpm_find_package NAME VERSION)
   string(REPLACE " " ";" EXTRA_ARGS "${ARGN}")
   find_package(${NAME} ${VERSION} ${EXTRA_ARGS} QUIET)
   if(${CPM_ARGS_NAME}_FOUND)
-    message(STATUS "${CPM_INDENT} using local package ${CPM_ARGS_NAME}@${VERSION}")
+    if(DEFINED ${CPM_ARGS_NAME}_VERSION)
+      set(VERSION ${${CPM_ARGS_NAME}_VERSION})
+    endif()
+    cpm_message(STATUS "${CPM_INDENT} Using local package ${CPM_ARGS_NAME}@${VERSION}")
     CPMRegisterPackage(${CPM_ARGS_NAME} "${VERSION}")
     set(CPM_PACKAGE_FOUND
         YES
@@ -221,11 +327,26 @@ endfunction()
 # finding the system library
 function(cpm_create_module_file Name)
   if(NOT CPM_DONT_UPDATE_MODULE_PATH)
-    # erase any previous modules
+    if(DEFINED CMAKE_FIND_PACKAGE_REDIRECTS_DIR)
+      # Redirect find_package calls to the CPM package. This is what FetchContent does when you set
+      # OVERRIDE_FIND_PACKAGE. The CMAKE_FIND_PACKAGE_REDIRECTS_DIR works for find_package in CONFIG
+      # mode, unlike the Find${Name}.cmake fallback. CMAKE_FIND_PACKAGE_REDIRECTS_DIR is not defined
+      # in script mode, or in CMake < 3.24.
+      # https://cmake.org/cmake/help/latest/module/FetchContent.html#fetchcontent-find-package-integration-examples
+      string(TOLOWER ${Name} NameLower)
+      file(WRITE ${CMAKE_FIND_PACKAGE_REDIRECTS_DIR}/${NameLower}-config.cmake
+           "include(\"\${CMAKE_CURRENT_LIST_DIR}/${NameLower}-extra.cmake\" OPTIONAL)\n"
+           "include(\"\${CMAKE_CURRENT_LIST_DIR}/${Name}Extra.cmake\" OPTIONAL)\n"
+      )
+      file(WRITE ${CMAKE_FIND_PACKAGE_REDIRECTS_DIR}/${NameLower}-config-version.cmake
+           "set(PACKAGE_VERSION_COMPATIBLE TRUE)\n" "set(PACKAGE_VERSION_EXACT TRUE)\n"
+      )
+    else()
       file(WRITE ${CPM_MODULE_PATH}/Find${Name}.cmake
            "include(\"${CPM_FILE}\")\n${ARGN}\nset(${Name}_FOUND TRUE)"
       )
     endif()
+  endif()
 endfunction()
 
 # Find a package locally or fallback to CPMAddPackage
@@ -240,14 +361,14 @@ function(CPMFindPackage)
     endif()
   endif()
 
-  if(CPM_DOWNLOAD_ALL)
+  set(downloadPackage ${CPM_DOWNLOAD_ALL})
-    CPMAddPackage(${ARGN})
+  if(DEFINED CPM_DOWNLOAD_${CPM_ARGS_NAME})
-    cpm_export_variables(${CPM_ARGS_NAME})
+    set(downloadPackage ${CPM_DOWNLOAD_${CPM_ARGS_NAME}})
-    return()
+  elseif(DEFINED ENV{CPM_DOWNLOAD_${CPM_ARGS_NAME}})
+    set(downloadPackage $ENV{CPM_DOWNLOAD_${CPM_ARGS_NAME}})
   endif()
-
+  if(downloadPackage)
-  cpm_check_if_package_already_added(${CPM_ARGS_NAME} "${CPM_ARGS_VERSION}")
+    CPMAddPackage(${ARGN})
-  if(CPM_PACKAGE_ALREADY_ADDED)
     cpm_export_variables(${CPM_ARGS_NAME})
     return()
   endif()
@@ -268,7 +389,7 @@ function(cpm_check_if_package_already_added CPM_ARGS_NAME CPM_ARGS_VERSION)
     if("${CPM_PACKAGE_VERSION}" VERSION_LESS "${CPM_ARGS_VERSION}")
       message(
         WARNING
-          "${CPM_INDENT} requires a newer version of ${CPM_ARGS_NAME} (${CPM_ARGS_VERSION}) than currently included (${CPM_PACKAGE_VERSION})."
+          "${CPM_INDENT} Requires a newer version of ${CPM_ARGS_NAME} (${CPM_ARGS_VERSION}) than currently included (${CPM_PACKAGE_VERSION})."
       )
     endif()
     cpm_get_fetch_properties(${CPM_ARGS_NAME})
@@ -325,11 +446,11 @@ function(cpm_parse_add_package_single_arg arg outArgs)
       set(packageType "git")
     else()
       # Give up
-      message(FATAL_ERROR "CPM: Can't determine package type of '${arg}'")
+      message(FATAL_ERROR "${CPM_INDENT} Can't determine package type of '${arg}'")
     endif()
   endif()
 
-  # For all packages we interpret @... as version. Only replace the last occurence. Thus URIs
+  # For all packages we interpret @... as version. Only replace the last occurrence. Thus URIs
   # containing '@' can be used
   string(REGEX REPLACE "@([^@]+)$" ";VERSION;\\1" out "${out}")
 
@@ -343,9 +464,9 @@ function(cpm_parse_add_package_single_arg arg outArgs)
     # We don't try to parse the version if it's not provided explicitly. cpm_get_version_from_url
     # should do this at a later point
   else()
-    # We should never get here. This is an assertion and hitting it means there's a bug in the code
+    # We should never get here. This is an assertion and hitting it means there's a problem with the
-    # above. A packageType was set, but not handled by this if-else.
+    # code above. A packageType was set, but not handled by this if-else.
-    message(FATAL_ERROR "CPM: Unsupported package type '${packageType}' of '${arg}'")
+    message(FATAL_ERROR "${CPM_INDENT} Unsupported package type '${packageType}' of '${arg}'")
   endif()
 
   set(${outArgs}
@@ -368,7 +489,7 @@ function(cpm_check_git_working_dir_is_clean repoPath gitTag isClean)
     return()
   endif()
 
-  # check for uncommited changes
+  # check for uncommitted changes
   execute_process(
     COMMAND ${GIT_EXECUTABLE} status --porcelain
     RESULT_VARIABLE resultGitStatus
@@ -378,7 +499,7 @@ function(cpm_check_git_working_dir_is_clean repoPath gitTag isClean)
   )
   if(resultGitStatus)
     # not supposed to happen, assume clean anyway
-    message(WARNING "Calling git status on folder ${repoPath} failed")
+    message(WARNING "${CPM_INDENT} Calling git status on folder ${repoPath} failed")
     set(${isClean}
         TRUE
         PARENT_SCOPE
@@ -394,7 +515,7 @@ function(cpm_check_git_working_dir_is_clean repoPath gitTag isClean)
     return()
   endif()
 
-  # check for commited changes
+  # check for committed changes
   execute_process(
     COMMAND ${GIT_EXECUTABLE} diff -s --exit-code ${gitTag}
     RESULT_VARIABLE resultGitDiff
@@ -416,15 +537,116 @@ function(cpm_check_git_working_dir_is_clean repoPath gitTag isClean)
 
 endfunction()
 
+# Add PATCH_COMMAND to CPM_ARGS_UNPARSED_ARGUMENTS. This method consumes a list of files in ARGN
+# then generates a `PATCH_COMMAND` appropriate for `ExternalProject_Add()`. This command is appended
+# to the parent scope's `CPM_ARGS_UNPARSED_ARGUMENTS`.
+function(cpm_add_patches)
+  # Return if no patch files are supplied.
+  if(NOT ARGN)
+    return()
+  endif()
+
+  # Find the patch program.
+  find_program(PATCH_EXECUTABLE patch)
+  if(CMAKE_HOST_WIN32 AND NOT PATCH_EXECUTABLE)
+    # The Windows git executable is distributed with patch.exe. Find the path to the executable, if
+    # it exists, then search `../usr/bin` and `../../usr/bin` for patch.exe.
+    find_package(Git QUIET)
+    if(GIT_EXECUTABLE)
+      get_filename_component(extra_search_path ${GIT_EXECUTABLE} DIRECTORY)
+      get_filename_component(extra_search_path_1up ${extra_search_path} DIRECTORY)
+      get_filename_component(extra_search_path_2up ${extra_search_path_1up} DIRECTORY)
+      find_program(
+        PATCH_EXECUTABLE patch HINTS "${extra_search_path_1up}/usr/bin"
+                                     "${extra_search_path_2up}/usr/bin"
+      )
+    endif()
+  endif()
+  if(NOT PATCH_EXECUTABLE)
+    message(FATAL_ERROR "Couldn't find `patch` executable to use with PATCHES keyword.")
+  endif()
+
+  # Create a temporary
+  set(temp_list ${CPM_ARGS_UNPARSED_ARGUMENTS})
+
+  # Ensure each file exists (or error out) and add it to the list.
+  set(first_item True)
+  foreach(PATCH_FILE ${ARGN})
+    # Make sure the patch file exists, if we can't find it, try again in the current directory.
+    if(NOT EXISTS "${PATCH_FILE}")
+      if(NOT EXISTS "${CMAKE_CURRENT_LIST_DIR}/${PATCH_FILE}")
+        message(FATAL_ERROR "Couldn't find patch file: '${PATCH_FILE}'")
+      endif()
+      set(PATCH_FILE "${CMAKE_CURRENT_LIST_DIR}/${PATCH_FILE}")
+    endif()
+
+    # Convert to absolute path for use with patch file command.
+    get_filename_component(PATCH_FILE "${PATCH_FILE}" ABSOLUTE)
+
+    # The first patch entry must be preceded by "PATCH_COMMAND" while the following items are
+    # preceded by "&&".
+    if(first_item)
+      set(first_item False)
+      list(APPEND temp_list "PATCH_COMMAND")
+    else()
+      list(APPEND temp_list "&&")
+    endif()
+    # Add the patch command to the list
+    list(APPEND temp_list "${PATCH_EXECUTABLE}" "-p1" "<" "${PATCH_FILE}")
+  endforeach()
+
+  # Move temp out into parent scope.
+  set(CPM_ARGS_UNPARSED_ARGUMENTS
+      ${temp_list}
+      PARENT_SCOPE
+  )
+
+endfunction()
+
+# method to overwrite internal FetchContent properties, to allow using CPM.cmake to overload
+# FetchContent calls. As these are internal cmake properties, this method should be used carefully
+# and may need modification in future CMake versions. Source:
+# https://github.com/Kitware/CMake/blob/dc3d0b5a0a7d26d43d6cfeb511e224533b5d188f/Modules/FetchContent.cmake#L1152
+function(cpm_override_fetchcontent contentName)
+  cmake_parse_arguments(PARSE_ARGV 1 arg "" "SOURCE_DIR;BINARY_DIR" "")
+  if(NOT "${arg_UNPARSED_ARGUMENTS}" STREQUAL "")
+    message(FATAL_ERROR "${CPM_INDENT} Unsupported arguments: ${arg_UNPARSED_ARGUMENTS}")
+  endif()
+
+  string(TOLOWER ${contentName} contentNameLower)
+  set(prefix "_FetchContent_${contentNameLower}")
+
+  set(propertyName "${prefix}_sourceDir")
+  define_property(
+    GLOBAL
+    PROPERTY ${propertyName}
+    BRIEF_DOCS "Internal implementation detail of FetchContent_Populate()"
+    FULL_DOCS "Details used by FetchContent_Populate() for ${contentName}"
+  )
+  set_property(GLOBAL PROPERTY ${propertyName} "${arg_SOURCE_DIR}")
+
+  set(propertyName "${prefix}_binaryDir")
+  define_property(
+    GLOBAL
+    PROPERTY ${propertyName}
+    BRIEF_DOCS "Internal implementation detail of FetchContent_Populate()"
+    FULL_DOCS "Details used by FetchContent_Populate() for ${contentName}"
+  )
+  set_property(GLOBAL PROPERTY ${propertyName} "${arg_BINARY_DIR}")
+
+  set(propertyName "${prefix}_populated")
+  define_property(
+    GLOBAL
+    PROPERTY ${propertyName}
+    BRIEF_DOCS "Internal implementation detail of FetchContent_Populate()"
+    FULL_DOCS "Details used by FetchContent_Populate() for ${contentName}"
+  )
+  set_property(GLOBAL PROPERTY ${propertyName} TRUE)
+endfunction()
+
 # Download and add a package from source
 function(CPMAddPackage)
-  list(LENGTH ARGN argnLength)
+  cpm_set_policies()
-  if(argnLength EQUAL 1)
-    cpm_parse_add_package_single_arg("${ARGN}" ARGN)
-
-    # The shorthand syntax implies EXCLUDE_FROM_ALL
-    set(ARGN "${ARGN};EXCLUDE_FROM_ALL;YES")
-  endif()
 
   set(oneValueArgs
       NAME
@@ -437,20 +659,37 @@ function(CPMAddPackage)
       BITBUCKET_REPOSITORY
       GIT_REPOSITORY
       SOURCE_DIR
-      DOWNLOAD_COMMAND
       FIND_PACKAGE_ARGUMENTS
       NO_CACHE
+      SYSTEM
       GIT_SHALLOW
       EXCLUDE_FROM_ALL
       SOURCE_SUBDIR
+      CUSTOM_CACHE_KEY
   )
 
-  set(multiValueArgs URL OPTIONS)
+  set(multiValueArgs URL OPTIONS DOWNLOAD_COMMAND PATCHES)
+
+  list(LENGTH ARGN argnLength)
+
+  # Parse single shorthand argument
+  if(argnLength EQUAL 1)
+    cpm_parse_add_package_single_arg("${ARGN}" ARGN)
+
+    # The shorthand syntax implies EXCLUDE_FROM_ALL and SYSTEM
+    set(ARGN "${ARGN};EXCLUDE_FROM_ALL;YES;SYSTEM;YES;")
+
+    # Parse URI shorthand argument
+  elseif(argnLength GREATER 1 AND "${ARGV0}" STREQUAL "URI")
+    list(REMOVE_AT ARGN 0 1) # remove "URI gh:<...>@version#tag"
+    cpm_parse_add_package_single_arg("${ARGV1}" ARGV0)
+
+    set(ARGN "${ARGV0};EXCLUDE_FROM_ALL;YES;SYSTEM;YES;${ARGN}")
+  endif()
 
   cmake_parse_arguments(CPM_ARGS "" "${oneValueArgs}" "${multiValueArgs}" "${ARGN}")
 
   # Set default values for arguments
-
   if(NOT DEFINED CPM_ARGS_VERSION)
     if(DEFINED CPM_ARGS_GIT_TAG)
       cpm_get_version_from_git_tag("${CPM_ARGS_GIT_TAG}" CPM_ARGS_VERSION)
@@ -516,7 +755,7 @@ function(CPMAddPackage)
   if(NOT DEFINED CPM_ARGS_NAME)
     message(
       FATAL_ERROR
-        "CPM: 'NAME' was not provided and couldn't be automatically inferred for package added with arguments: '${ARGN}'"
+        "${CPM_INDENT} 'NAME' was not provided and couldn't be automatically inferred for package added with arguments: '${ARGN}'"
     )
   endif()
 
@@ -535,8 +774,11 @@ function(CPMAddPackage)
       NAME "${CPM_ARGS_NAME}"
       SOURCE_DIR "${PACKAGE_SOURCE}"
       EXCLUDE_FROM_ALL "${CPM_ARGS_EXCLUDE_FROM_ALL}"
+      SYSTEM "${CPM_ARGS_SYSTEM}"
+      PATCHES "${CPM_ARGS_PATCHES}"
       OPTIONS "${CPM_ARGS_OPTIONS}"
       SOURCE_SUBDIR "${CPM_ARGS_SOURCE_SUBDIR}"
+      DOWNLOAD_ONLY "${DOWNLOAD_ONLY}"
       FORCE True
     )
     cpm_export_variables(${CPM_ARGS_NAME})
@@ -554,6 +796,7 @@ function(CPMAddPackage)
     return()
   endif()
 
+  if(NOT CPM_ARGS_FORCE)
     if(CPM_USE_LOCAL_PACKAGES OR CPM_LOCAL_PACKAGES_ONLY)
       cpm_find_package(${CPM_ARGS_NAME} "${CPM_ARGS_VERSION}" ${CPM_ARGS_FIND_PACKAGE_ARGUMENTS})
 
@@ -565,10 +808,11 @@ function(CPMAddPackage)
       if(CPM_LOCAL_PACKAGES_ONLY)
         message(
           SEND_ERROR
-          "CPM: ${CPM_ARGS_NAME} not found via find_package(${CPM_ARGS_NAME} ${CPM_ARGS_VERSION})"
+            "${CPM_INDENT} ${CPM_ARGS_NAME} not found via find_package(${CPM_ARGS_NAME} ${CPM_ARGS_VERSION})"
         )
       endif()
     endif()
+  endif()
 
   CPMRegisterPackage("${CPM_ARGS_NAME}" "${CPM_ARGS_VERSION}")
 
@@ -587,41 +831,98 @@ function(CPMAddPackage)
     set(CPM_FETCHCONTENT_BASE_DIR ${CMAKE_BINARY_DIR}/_deps)
   endif()
 
+  cpm_add_patches(${CPM_ARGS_PATCHES})
+
   if(DEFINED CPM_ARGS_DOWNLOAD_COMMAND)
     list(APPEND CPM_ARGS_UNPARSED_ARGUMENTS DOWNLOAD_COMMAND ${CPM_ARGS_DOWNLOAD_COMMAND})
   elseif(DEFINED CPM_ARGS_SOURCE_DIR)
     list(APPEND CPM_ARGS_UNPARSED_ARGUMENTS SOURCE_DIR ${CPM_ARGS_SOURCE_DIR})
+    if(NOT IS_ABSOLUTE ${CPM_ARGS_SOURCE_DIR})
+      # Expand `CPM_ARGS_SOURCE_DIR` relative path. This is important because EXISTS doesn't work
+      # for relative paths.
+      get_filename_component(
+        source_directory ${CPM_ARGS_SOURCE_DIR} REALPATH BASE_DIR ${CMAKE_CURRENT_BINARY_DIR}
+      )
+    else()
+      set(source_directory ${CPM_ARGS_SOURCE_DIR})
+    endif()
+    if(NOT EXISTS ${source_directory})
+      string(TOLOWER ${CPM_ARGS_NAME} lower_case_name)
+      # remove timestamps so CMake will re-download the dependency
+      file(REMOVE_RECURSE "${CPM_FETCHCONTENT_BASE_DIR}/${lower_case_name}-subbuild")
+    endif()
   elseif(CPM_SOURCE_CACHE AND NOT CPM_ARGS_NO_CACHE)
     string(TOLOWER ${CPM_ARGS_NAME} lower_case_name)
     set(origin_parameters ${CPM_ARGS_UNPARSED_ARGUMENTS})
     list(SORT origin_parameters)
+    if(CPM_ARGS_CUSTOM_CACHE_KEY)
+      # Application set a custom unique directory name
+      set(download_directory ${CPM_SOURCE_CACHE}/${lower_case_name}/${CPM_ARGS_CUSTOM_CACHE_KEY})
+    elseif(CPM_USE_NAMED_CACHE_DIRECTORIES)
+      string(SHA1 origin_hash "${origin_parameters};NEW_CACHE_STRUCTURE_TAG")
+      cpm_get_shortest_hash(
+        "${CPM_SOURCE_CACHE}/${lower_case_name}" # source cache directory
+        "${origin_hash}" # Input hash
+        origin_hash # Computed hash
+      )
+      set(download_directory ${CPM_SOURCE_CACHE}/${lower_case_name}/${origin_hash}/${CPM_ARGS_NAME})
+    else()
       string(SHA1 origin_hash "${origin_parameters}")
+      cpm_get_shortest_hash(
+        "${CPM_SOURCE_CACHE}/${lower_case_name}" # source cache directory
+        "${origin_hash}" # Input hash
+        origin_hash # Computed hash
+      )
       set(download_directory ${CPM_SOURCE_CACHE}/${lower_case_name}/${origin_hash})
+    endif()
     # Expand `download_directory` relative path. This is important because EXISTS doesn't work for
     # relative paths.
     get_filename_component(download_directory ${download_directory} ABSOLUTE)
     list(APPEND CPM_ARGS_UNPARSED_ARGUMENTS SOURCE_DIR ${download_directory})
-    if(EXISTS ${download_directory})
-      # avoid FetchContent modules to improve performance
-      set(${CPM_ARGS_NAME}_BINARY_DIR ${CPM_FETCHCONTENT_BASE_DIR}/${lower_case_name}-build)
-      set(${CPM_ARGS_NAME}_ADDED YES)
-      set(${CPM_ARGS_NAME}_SOURCE_DIR ${download_directory})
 
-      if(DEFINED CPM_ARGS_GIT_TAG)
+    if(CPM_SOURCE_CACHE)
+      file(LOCK ${download_directory}/../cmake.lock)
+    endif()
+
+    if(EXISTS ${download_directory})
+      if(CPM_SOURCE_CACHE)
+        file(LOCK ${download_directory}/../cmake.lock RELEASE)
+      endif()
+
+      cpm_store_fetch_properties(
+        ${CPM_ARGS_NAME} "${download_directory}"
+        "${CPM_FETCHCONTENT_BASE_DIR}/${lower_case_name}-build"
+      )
+      cpm_get_fetch_properties("${CPM_ARGS_NAME}")
+
+      if(DEFINED CPM_ARGS_GIT_TAG AND NOT (PATCH_COMMAND IN_LIST CPM_ARGS_UNPARSED_ARGUMENTS))
         # warn if cache has been changed since checkout
         cpm_check_git_working_dir_is_clean(${download_directory} ${CPM_ARGS_GIT_TAG} IS_CLEAN)
         if(NOT ${IS_CLEAN})
-          message(WARNING "Cache for ${CPM_ARGS_NAME} (${download_directory}) is dirty")
+          message(
+            WARNING "${CPM_INDENT} Cache for ${CPM_ARGS_NAME} (${download_directory}) is dirty"
+          )
         endif()
       endif()
 
       cpm_add_subdirectory(
-        "${CPM_ARGS_NAME}" "${DOWNLOAD_ONLY}"
+        "${CPM_ARGS_NAME}"
-        "${${CPM_ARGS_NAME}_SOURCE_DIR}/${CPM_ARGS_SOURCE_SUBDIR}" "${${CPM_ARGS_NAME}_BINARY_DIR}"
+        "${DOWNLOAD_ONLY}"
-        "${CPM_ARGS_EXCLUDE_FROM_ALL}" "${CPM_ARGS_OPTIONS}"
+        "${${CPM_ARGS_NAME}_SOURCE_DIR}/${CPM_ARGS_SOURCE_SUBDIR}"
+        "${${CPM_ARGS_NAME}_BINARY_DIR}"
+        "${CPM_ARGS_EXCLUDE_FROM_ALL}"
+        "${CPM_ARGS_SYSTEM}"
+        "${CPM_ARGS_OPTIONS}"
       )
-      set(CPM_SKIP_FETCH TRUE)
       set(PACKAGE_INFO "${PACKAGE_INFO} at ${download_directory}")
+
+      # As the source dir is already cached/populated, we override the call to FetchContent.
+      set(CPM_SKIP_FETCH TRUE)
+      cpm_override_fetchcontent(
+        "${lower_case_name}" SOURCE_DIR "${${CPM_ARGS_NAME}_SOURCE_DIR}/${CPM_ARGS_SOURCE_SUBDIR}"
+        BINARY_DIR "${${CPM_ARGS_NAME}_BINARY_DIR}"
+      )
+
     else()
       # Enable shallow clone when GIT_TAG is not a commit hash. Our guess may not be accurate, but
       # it should guarantee no commit hash get mis-detected.
@@ -638,7 +939,9 @@ function(CPMAddPackage)
     endif()
   endif()
 
-  cpm_create_module_file(${CPM_ARGS_NAME} "CPMAddPackage(${ARGN})")
+  if(NOT "${DOWNLOAD_ONLY}")
+    cpm_create_module_file(${CPM_ARGS_NAME} "CPMAddPackage(\"${ARGN}\")")
+  endif()
 
   if(CPM_PACKAGE_LOCK_ENABLED)
     if((CPM_ARGS_VERSION AND NOT CPM_ARGS_SOURCE_DIR) OR CPM_INCLUDE_ALL_IN_PACKAGE_LOCK)
@@ -650,20 +953,52 @@ function(CPMAddPackage)
     endif()
   endif()
 
-  message(
+  cpm_message(
-    STATUS "${CPM_INDENT} adding package ${CPM_ARGS_NAME}@${CPM_ARGS_VERSION} (${PACKAGE_INFO})"
+    STATUS "${CPM_INDENT} Adding package ${CPM_ARGS_NAME}@${CPM_ARGS_VERSION} (${PACKAGE_INFO})"
   )
 
   if(NOT CPM_SKIP_FETCH)
+    # CMake 3.28 added EXCLUDE, SYSTEM (3.25), and SOURCE_SUBDIR (3.18) to FetchContent_Declare.
+    # Calling FetchContent_MakeAvailable will then internally forward these options to
+    # add_subdirectory. Up until these changes, we had to call FetchContent_Populate and
+    # add_subdirectory separately, which is no longer necessary and has been deprecated as of 3.30.
+    # A Bug in CMake prevents us to use the non-deprecated functions until 3.30.3.
+    set(fetchContentDeclareExtraArgs "")
+    if(${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.30.3")
+      if(${CPM_ARGS_EXCLUDE_FROM_ALL})
+        list(APPEND fetchContentDeclareExtraArgs EXCLUDE_FROM_ALL)
+      endif()
+      if(${CPM_ARGS_SYSTEM})
+        list(APPEND fetchContentDeclareExtraArgs SYSTEM)
+      endif()
+      if(DEFINED CPM_ARGS_SOURCE_SUBDIR)
+        list(APPEND fetchContentDeclareExtraArgs SOURCE_SUBDIR ${CPM_ARGS_SOURCE_SUBDIR})
+      endif()
+      # For CMake version <3.28 OPTIONS are parsed in cpm_add_subdirectory
+      if(CPM_ARGS_OPTIONS AND NOT DOWNLOAD_ONLY)
+        foreach(OPTION ${CPM_ARGS_OPTIONS})
+          cpm_parse_option("${OPTION}")
+          set(${OPTION_KEY} "${OPTION_VALUE}")
+        endforeach()
+      endif()
+    endif()
     cpm_declare_fetch(
-      "${CPM_ARGS_NAME}" "${CPM_ARGS_VERSION}" "${PACKAGE_INFO}" "${CPM_ARGS_UNPARSED_ARGUMENTS}"
+      "${CPM_ARGS_NAME}" ${fetchContentDeclareExtraArgs} "${CPM_ARGS_UNPARSED_ARGUMENTS}"
     )
-    cpm_fetch_package("${CPM_ARGS_NAME}" populated)
+
-    if(${populated})
+    cpm_fetch_package("${CPM_ARGS_NAME}" ${DOWNLOAD_ONLY} populated ${CPM_ARGS_UNPARSED_ARGUMENTS})
+    if(CPM_SOURCE_CACHE AND download_directory)
+      file(LOCK ${download_directory}/../cmake.lock RELEASE)
+    endif()
+    if(${populated} AND ${CMAKE_VERSION} VERSION_LESS "3.30.3")
       cpm_add_subdirectory(
-        "${CPM_ARGS_NAME}" "${DOWNLOAD_ONLY}"
+        "${CPM_ARGS_NAME}"
-        "${${CPM_ARGS_NAME}_SOURCE_DIR}/${CPM_ARGS_SOURCE_SUBDIR}" "${${CPM_ARGS_NAME}_BINARY_DIR}"
+        "${DOWNLOAD_ONLY}"
-        "${CPM_ARGS_EXCLUDE_FROM_ALL}" "${CPM_ARGS_OPTIONS}"
+        "${${CPM_ARGS_NAME}_SOURCE_DIR}/${CPM_ARGS_SOURCE_SUBDIR}"
+        "${${CPM_ARGS_NAME}_BINARY_DIR}"
+        "${CPM_ARGS_EXCLUDE_FROM_ALL}"
+        "${CPM_ARGS_SYSTEM}"
+        "${CPM_ARGS_OPTIONS}"
       )
     endif()
     cpm_get_fetch_properties("${CPM_ARGS_NAME}")
@@ -678,7 +1013,7 @@ macro(CPMGetPackage Name)
   if(DEFINED "CPM_DECLARATION_${Name}")
     CPMAddPackage(NAME ${Name})
   else()
-    message(SEND_ERROR "Cannot retrieve package ${Name}: no declaration available")
+    message(SEND_ERROR "${CPM_INDENT} Cannot retrieve package ${Name}: no declaration available")
   endif()
 endmacro()
 
@@ -696,10 +1031,14 @@ macro(cpm_export_variables name)
       "${${name}_ADDED}"
       PARENT_SCOPE
   )
+  set(CPM_LAST_PACKAGE_NAME
+      "${name}"
+      PARENT_SCOPE
+  )
 endmacro()
 
 # declares a package, so that any call to CPMAddPackage for the package name will use these
-# arguments instead. Previous declarations will not be overriden.
+# arguments instead. Previous declarations will not be overridden.
 macro(CPMDeclarePackage Name)
   if(NOT DEFINED "CPM_DECLARATION_${Name}")
     set("CPM_DECLARATION_${Name}" "${ARGN}")
@@ -722,7 +1061,7 @@ function(cpm_add_comment_to_package_lock Name)
   endif()
 endfunction()
 
-# includes the package lock file if it exists and creates a target `cpm-write-package-lock` to
+# includes the package lock file if it exists and creates a target `cpm-update-package-lock` to
 # update it
 macro(CPMUsePackageLock file)
   if(NOT CPM_DONT_CREATE_PACKAGE_LOCK)
@@ -762,9 +1101,9 @@ function(CPMGetPackageVersion PACKAGE OUTPUT)
 endfunction()
 
 # declares a package in FetchContent_Declare
-function(cpm_declare_fetch PACKAGE VERSION INFO)
+function(cpm_declare_fetch PACKAGE)
   if(${CPM_DRY_RUN})
-    message(STATUS "${CPM_INDENT} package not declared (dry run)")
+    cpm_message(STATUS "${CPM_INDENT} Package not declared (dry run)")
     return()
   endif()
 
@@ -776,18 +1115,32 @@ function(cpm_get_fetch_properties PACKAGE)
   if(${CPM_DRY_RUN})
     return()
   endif()
-  FetchContent_GetProperties(${PACKAGE})
+
-  string(TOLOWER ${PACKAGE} lpackage)
   set(${PACKAGE}_SOURCE_DIR
-      "${${lpackage}_SOURCE_DIR}"
+      "${CPM_PACKAGE_${PACKAGE}_SOURCE_DIR}"
       PARENT_SCOPE
   )
   set(${PACKAGE}_BINARY_DIR
-      "${${lpackage}_BINARY_DIR}"
+      "${CPM_PACKAGE_${PACKAGE}_BINARY_DIR}"
       PARENT_SCOPE
   )
 endfunction()
 
+function(cpm_store_fetch_properties PACKAGE source_dir binary_dir)
+  if(${CPM_DRY_RUN})
+    return()
+  endif()
+
+  set(CPM_PACKAGE_${PACKAGE}_SOURCE_DIR
+      "${source_dir}"
+      CACHE INTERNAL ""
+  )
+  set(CPM_PACKAGE_${PACKAGE}_BINARY_DIR
+      "${binary_dir}"
+      CACHE INTERNAL ""
+  )
+endfunction()
+
 # adds a package as a subdirectory if viable, according to provided options
 function(
   cpm_add_subdirectory
@@ -796,22 +1149,23 @@ function(
   SOURCE_DIR
   BINARY_DIR
   EXCLUDE
+  SYSTEM
   OPTIONS
 )
+
   if(NOT DOWNLOAD_ONLY AND EXISTS ${SOURCE_DIR}/CMakeLists.txt)
-    if(EXCLUDE)
-      set(addSubdirectoryExtraArgs EXCLUDE_FROM_ALL)
-    else()
     set(addSubdirectoryExtraArgs "")
+    if(EXCLUDE)
+      list(APPEND addSubdirectoryExtraArgs EXCLUDE_FROM_ALL)
+    endif()
+    if("${SYSTEM}" AND "${CMAKE_VERSION}" VERSION_GREATER_EQUAL "3.25")
+      # https://cmake.org/cmake/help/latest/prop_dir/SYSTEM.html#prop_dir:SYSTEM
+      list(APPEND addSubdirectoryExtraArgs SYSTEM)
     endif()
     if(OPTIONS)
-      # the policy allows us to change options without caching
-      cmake_policy(SET CMP0077 NEW)
-      set(CMAKE_POLICY_DEFAULT_CMP0077 NEW)
-
       foreach(OPTION ${OPTIONS})
-        cpm_parse_option(${OPTION})
+        cpm_parse_option("${OPTION}")
-        set(${OPTION_KEY} ${OPTION_VALUE})
+        set(${OPTION_KEY} "${OPTION_VALUE}")
       endforeach()
     endif()
     set(CPM_OLD_INDENT "${CPM_INDENT}")
@@ -823,13 +1177,13 @@ endfunction()
 
 # downloads a previously declared package via FetchContent and exports the variables
 # `${PACKAGE}_SOURCE_DIR` and `${PACKAGE}_BINARY_DIR` to the parent scope
-function(cpm_fetch_package PACKAGE populated)
+function(cpm_fetch_package PACKAGE DOWNLOAD_ONLY populated)
   set(${populated}
       FALSE
       PARENT_SCOPE
   )
   if(${CPM_DRY_RUN})
-    message(STATUS "${CPM_INDENT} package ${PACKAGE} not fetched (dry run)")
+    cpm_message(STATUS "${CPM_INDENT} Package ${PACKAGE} not fetched (dry run)")
     return()
   endif()
 
@@ -838,13 +1192,34 @@ function(cpm_fetch_package PACKAGE populated)
   string(TOLOWER "${PACKAGE}" lower_case_name)
 
   if(NOT ${lower_case_name}_POPULATED)
+    if(${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.30.3")
+      if(DOWNLOAD_ONLY)
+        # MakeAvailable will call add_subdirectory internally which is not what we want when
+        # DOWNLOAD_ONLY is set. Populate will only download the dependency without adding it to the
+        # build
+        FetchContent_Populate(
+          ${PACKAGE}
+          SOURCE_DIR "${CPM_FETCHCONTENT_BASE_DIR}/${lower_case_name}-src"
+          BINARY_DIR "${CPM_FETCHCONTENT_BASE_DIR}/${lower_case_name}-build"
+          SUBBUILD_DIR "${CPM_FETCHCONTENT_BASE_DIR}/${lower_case_name}-subbuild"
+          ${ARGN}
+        )
+      else()
+        FetchContent_MakeAvailable(${PACKAGE})
+      endif()
+    else()
       FetchContent_Populate(${PACKAGE})
+    endif()
     set(${populated}
         TRUE
         PARENT_SCOPE
     )
   endif()
 
+  cpm_store_fetch_properties(
+    ${CPM_ARGS_NAME} ${${lower_case_name}_SOURCE_DIR} ${${lower_case_name}_BINARY_DIR}
+  )
+
   set(${PACKAGE}_SOURCE_DIR
       ${${lower_case_name}_SOURCE_DIR}
       PARENT_SCOPE
@@ -857,15 +1232,15 @@ endfunction()
 
 # splits a package option
 function(cpm_parse_option OPTION)
-  string(REGEX MATCH "^[^ ]+" OPTION_KEY ${OPTION})
+  string(REGEX MATCH "^[^ ]+" OPTION_KEY "${OPTION}")
-  string(LENGTH ${OPTION} OPTION_LENGTH)
+  string(LENGTH "${OPTION}" OPTION_LENGTH)
-  string(LENGTH ${OPTION_KEY} OPTION_KEY_LENGTH)
+  string(LENGTH "${OPTION_KEY}" OPTION_KEY_LENGTH)
   if(OPTION_KEY_LENGTH STREQUAL OPTION_LENGTH)
     # no value for key provided, assume user wants to set option to "ON"
     set(OPTION_VALUE "ON")
   else()
     math(EXPR OPTION_KEY_LENGTH "${OPTION_KEY_LENGTH}+1")
-    string(SUBSTRING ${OPTION} "${OPTION_KEY_LENGTH}" "-1" OPTION_VALUE)
+    string(SUBSTRING "${OPTION}" "${OPTION_KEY_LENGTH}" "-1" OPTION_VALUE)
   endif()
   set(OPTION_KEY
       "${OPTION_KEY}"
@@ -895,7 +1270,7 @@ function(cpm_get_version_from_git_tag GIT_TAG RESULT)
   endif()
 endfunction()
 
-# guesses if the git tag is a commit hash or an actual tag or a branch nane.
+# guesses if the git tag is a commit hash or an actual tag or a branch name.
 function(cpm_is_git_tag_commit_hash GIT_TAG RESULT)
   string(LENGTH "${GIT_TAG}" length)
   # full hash has 40 characters, and short hash has at least 7 characters.
@@ -928,14 +1303,17 @@ function(cpm_prettify_package_arguments OUT_VAR IS_IN_COMMENT)
       DOWNLOAD_ONLY
       GITHUB_REPOSITORY
       GITLAB_REPOSITORY
+      BITBUCKET_REPOSITORY
       GIT_REPOSITORY
       SOURCE_DIR
-      DOWNLOAD_COMMAND
       FIND_PACKAGE_ARGUMENTS
       NO_CACHE
+      SYSTEM
       GIT_SHALLOW
+      EXCLUDE_FROM_ALL
+      SOURCE_SUBDIR
   )
-  set(multiValueArgs OPTIONS)
+  set(multiValueArgs URL OPTIONS DOWNLOAD_COMMAND)
   cmake_parse_arguments(CPM_ARGS "" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
 
   foreach(oneArgName ${oneValueArgs})

cmake/get_cpm.cmake

@@ -1,8 +1,11 @@
+# SPDX-License-Identifier: MIT
+#
+# SPDX-FileCopyrightText: Copyright (c) 2019-2023 Lars Melchior and contributors
+
 set(CPM_DOWNLOAD_VERSION 1.0.0-development-version)
+set(CPM_HASH_SUM "CPM_HASH_SUM_PLACEHOLDER")
 
 if(CPM_SOURCE_CACHE)
-  # Expand relative path. This is important if the provided path contains a tilde (~)
-  get_filename_component(CPM_SOURCE_CACHE ${CPM_SOURCE_CACHE} ABSOLUTE)
   set(CPM_DOWNLOAD_LOCATION "${CPM_SOURCE_CACHE}/cpm/CPM_${CPM_DOWNLOAD_VERSION}.cmake")
 elseif(DEFINED ENV{CPM_SOURCE_CACHE})
   set(CPM_DOWNLOAD_LOCATION "$ENV{CPM_SOURCE_CACHE}/cpm/CPM_${CPM_DOWNLOAD_VERSION}.cmake")
@@ -10,12 +13,12 @@ else()
   set(CPM_DOWNLOAD_LOCATION "${CMAKE_BINARY_DIR}/cmake/CPM_${CPM_DOWNLOAD_VERSION}.cmake")
 endif()
 
-if(NOT (EXISTS ${CPM_DOWNLOAD_LOCATION}))
+# Expand relative path. This is important if the provided path contains a tilde (~)
-  message(STATUS "Downloading CPM.cmake to ${CPM_DOWNLOAD_LOCATION}")
+get_filename_component(CPM_DOWNLOAD_LOCATION ${CPM_DOWNLOAD_LOCATION} ABSOLUTE)
+
 file(DOWNLOAD
      https://github.com/cpm-cmake/CPM.cmake/releases/download/v${CPM_DOWNLOAD_VERSION}/CPM.cmake
-       ${CPM_DOWNLOAD_LOCATION}
+     ${CPM_DOWNLOAD_LOCATION} EXPECTED_HASH SHA256=${CPM_HASH_SUM}
 )
-endif()
 
 include(${CPM_DOWNLOAD_LOCATION})

cmake/testing.cmake

@@ -32,13 +32,13 @@ function(ASSERT_DEFINED KEY)
   if(DEFINED ${KEY})
     message(STATUS "test passed: '${KEY}' is defined")
   else()
-    message(FATAL_ERROR "assertion failed: '${KEY}' is not defiend")
+    message(FATAL_ERROR "assertion failed: '${KEY}' is not defined")
   endif()
 endfunction()
 
 function(ASSERT_NOT_DEFINED KEY)
   if(DEFINED ${KEY})
-    message(FATAL_ERROR "assertion failed: '${KEY}' is defiend (${${KEY}})")
+    message(FATAL_ERROR "assertion failed: '${KEY}' is defined (${${KEY}})")
   else()
     message(STATUS "test passed: '${KEY}' is not defined")
   endif()
@@ -79,3 +79,16 @@ function(ASSERT_NOT_EXISTS file)
     message(FATAL_ERROR "assertion failed: file ${file} exists")
   endif()
 endfunction()
+
+function(ASSERT_CONTENTS_EQUAL file content)
+  if(EXISTS ${file})
+    file(READ ${file} file_content)
+    if(content STREQUAL file_content)
+      message(STATUS "test passed: '${file}' exists and contains '${content}'")
+    else()
+      message(FATAL_ERROR "assertion failed: file '${file}' does not contain expected content.")
+    endif()
+  else()
+    message(FATAL_ERROR "assertion failed: file '${file} does not exist")
+  endif()
+endfunction()

examples/benchmark/CMakeLists.txt

@@ -11,7 +11,7 @@ CPMAddPackage("gh:cpm-cmake/testpack-fibonacci@2.0")
 CPMAddPackage(
   NAME benchmark
   GITHUB_REPOSITORY google/benchmark
-  VERSION 1.5.2
+  VERSION 1.7.1
   OPTIONS "BENCHMARK_ENABLE_TESTING Off"
 )
 

examples/boost/CMakeLists.txt

@@ -11,9 +11,14 @@ target_compile_features(CPMExampleBoost PRIVATE cxx_std_17)
 
 include(../../cmake/CPM.cmake)
 
-# boost-cmake currently doesn't tag versions, so we use the according boost version
+CPMAddPackage(
-CPMAddPackage("gh:Orphis/boost-cmake#7f97a08b64bd5d2e53e932ddf80c40544cf45edf@1.71.0")
+  NAME Boost
+  VERSION 1.86.0 # Versions less than 1.85.0 may need patches for installation targets.
+  URL https://github.com/boostorg/boost/releases/download/boost-1.86.0/boost-1.86.0-cmake.tar.xz
+  URL_HASH SHA256=2c5ec5edcdff47ff55e27ed9560b0a0b94b07bd07ed9928b476150e16b0efc57
+  OPTIONS "BOOST_ENABLE_CMAKE ON" "BOOST_SKIP_INSTALL_RULES ON" # Set `OFF` for installation
+          "BUILD_SHARED_LIBS OFF" "BOOST_INCLUDE_LIBRARIES container\\\;asio" # Note the escapes!
+)
 
-find_package(Threads REQUIRED)
+# `Boost::headers` is also valid
-
+target_link_libraries(CPMExampleBoost PRIVATE Boost::asio Boost::container)
-target_link_libraries(CPMExampleBoost PRIVATE Boost::system Threads::Threads)

examples/boost/main.cpp

@@ -9,14 +9,22 @@
 //
 
 #include <boost/asio.hpp>
+#include <boost/container/devector.hpp>
 #include <boost/date_time/posix_time/posix_time.hpp>
 #include <iostream>
+#include <string>
 
-void print(const boost::system::error_code& /*e*/) { std::cout << "Hello, world!" << std::endl; }
+boost::container::devector<std::string> strings;
+
+void print(const boost::system::error_code& /*e*/) {
+  for (const auto& a : strings) std::cout << a;
+}
 
 int main() {
   boost::asio::io_service io;
 
+  strings.push_back("Hello, world!\n");
+
   boost::asio::deadline_timer t(io, boost::posix_time::seconds(1));
   t.async_wait(&print);
 

examples/build_all.py

@@ -26,7 +26,7 @@ for example in examples:
   print("running example %s" % example.name)
   print("================" + ('=' * len(example.name)))
   project = Path(".") / 'build' / example.name
-  configure = runCommand('cmake -H%s -B%s' % (example, project))
+  configure = runCommand('cmake -S%s -B%s' % (example, project))
   print('  ' + '\n  '.join([line for line in configure.split('\n') if 'CPM:' in line]))
   build = runCommand('cmake --build %s -- -j%i' % (project, os.cpu_count() / 2))
   print('  ' + '\n  '.join([line for line in build.split('\n') if 'Built target' in line]))

examples/catch2/CMakeLists.txt

@@ -7,12 +7,12 @@ project(CPMExampleCatch2)
 include(../../cmake/CPM.cmake)
 
 CPMAddPackage("gh:cpm-cmake/testpack-fibonacci@2.0")
-CPMAddPackage("gh:catchorg/Catch2@2.13.4")
+CPMAddPackage("gh:catchorg/Catch2@3.4.0")
 
 # ---- Create binary ----
 
 add_executable(CPMExampleCatch2 main.cpp)
-target_link_libraries(CPMExampleCatch2 fibonacci Catch2)
+target_link_libraries(CPMExampleCatch2 fibonacci Catch2::Catch2WithMain)
 target_compile_features(CPMExampleCatch2 PRIVATE cxx_std_17)
 
 # ---- Enable testing ----

examples/catch2/main.cpp

@@ -1,8 +1,6 @@
-#define CATCH_CONFIG_MAIN
-
 #include <fibonacci.h>
 
-#include <catch2/catch.hpp>
+#include <catch2/catch_test_macros.hpp>
 
 TEST_CASE("fibonacci") {
   REQUIRE(fibonacci(0) == 0);

examples/doctest/CMakeLists.txt

@@ -7,7 +7,7 @@ project(CPMExampleDoctest)
 include(../../cmake/CPM.cmake)
 
 CPMAddPackage("gh:cpm-cmake/testpack-fibonacci@2.0")
-CPMAddPackage("gh:onqtam/doctest#2.4.5")
+CPMAddPackage("gh:onqtam/doctest@2.4.9")
 
 # ---- Create binary ----
 

examples/entt/CMakeLists.txt

@@ -9,8 +9,7 @@ include(../../cmake/CPM.cmake)
 CPMAddPackage(
   NAME EnTT
   VERSION 3.1.1
-  GITHUB_REPOSITORY skypjack/entt
+  GITHUB_REPOSITORY skypjack/entt # EnTT's CMakeLists screws with configuration options
-  # EnTT's CMakeLists screws with configuration options
   DOWNLOAD_ONLY True
 )
 

examples/fmt/CMakeLists.txt

@@ -1,6 +1,6 @@
 cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
 
-project(CPMJSONExample)
+project(CPMFmtExample)
 
 # ---- Dependencies ----
 

examples/gtest/CMakeLists.txt

@@ -11,8 +11,8 @@ CPMAddPackage("gh:cpm-cmake/testpack-fibonacci@2.0")
 CPMAddPackage(
   NAME googletest
   GITHUB_REPOSITORY google/googletest
-  GIT_TAG release-1.10.0
+  GIT_TAG release-1.12.1
-  VERSION 1.10.0
+  VERSION 1.12.1
   OPTIONS "INSTALL_GTEST OFF" "gtest_force_shared_crt"
 )
 

examples/highway/CMakeLists.txt

@@ -0,0 +1,28 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMExamplePatchHighway)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+
+# Google's highway Includes a SIMD sorting function that is faster than x86-simd-sort for larger
+# arrays. See: https://github.com/google/highway/blob/master/g3doc/quick_reference.md
+CPMAddPackage(
+  NAME highway
+  URL https://github.com/google/highway/archive/refs/tags/1.1.0.tar.gz
+  URL_HASH SHA256=354a8b4539b588e70b98ec70844273e3f2741302c4c377bcc4e81b3d1866f7c9
+  PATCHES "highway.patch" # This adds SYSTEM to the includes.
+  OPTIONS "HWY_ENABLE_EXAMPLES OFF" "HWY_ENABLE_INSTALL OFF" "HWY_ENABLE_TESTS OFF"
+)
+
+# ---- Executable ----
+
+if(LINUX)
+  # This would cause a float compare error inside the highway header code if the patch is NOT
+  # applied.
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wfloat-equal")
+endif()
+
+add_executable(CPMExamplePatchHighway "main.cpp")
+target_link_libraries(CPMExamplePatchHighway hwy hwy_contrib)

examples/highway/highway.patch

@@ -0,0 +1,28 @@
+Common subdirectories: a/.bcr and b/.bcr
+Common subdirectories: a/.github and b/.github
+diff -u a/CMakeLists.txt b/CMakeLists.txt
+--- a/CMakeLists.txt	2024-05-21 12:50:37.738318520 -0500
++++ b/CMakeLists.txt	2024-05-21 12:49:59.914226871 -0500
+@@ -350,7 +350,7 @@
+ target_compile_options(hwy PRIVATE ${HWY_FLAGS})
+ set_property(TARGET hwy PROPERTY POSITION_INDEPENDENT_CODE ON)
+ set_target_properties(hwy PROPERTIES VERSION ${LIBRARY_VERSION} SOVERSION ${LIBRARY_SOVERSION})
+-target_include_directories(hwy PUBLIC
++target_include_directories(hwy SYSTEM PUBLIC
+     $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}>
+     $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>)
+ target_compile_features(hwy PUBLIC cxx_std_11)
+@@ -370,7 +370,7 @@
+ target_compile_options(hwy_contrib PRIVATE ${HWY_FLAGS})
+ set_property(TARGET hwy_contrib PROPERTY POSITION_INDEPENDENT_CODE ON)
+ set_target_properties(hwy_contrib PROPERTIES VERSION ${LIBRARY_VERSION} SOVERSION ${LIBRARY_SOVERSION})
+-target_include_directories(hwy_contrib PUBLIC
++target_include_directories(hwy_contrib SYSTEM PUBLIC
+     $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}>
+     $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>)
+ target_compile_features(hwy_contrib PUBLIC cxx_std_11)
+Common subdirectories: a/cmake and b/cmake
+Common subdirectories: a/debian and b/debian
+Common subdirectories: a/docs and b/docs
+Common subdirectories: a/g3doc and b/g3doc
+Common subdirectories: a/hwy and b/hwy

examples/highway/main.cpp

@@ -0,0 +1,27 @@
+#include <hwy/contrib/sort/vqsort.h>  // hwy::VQSort() for large data sets
+
+#include <cstdint>
+#include <random>
+#include <vector>
+
+// Use hwy::VQSort to sort larger vectors
+inline void sort_large(std::vector<double>& v) {
+  hwy::VQSort(v.data(), v.size(), hwy::SortAscending{});
+}
+
+int main(int, char**) {
+  std::random_device random_device;
+  std::default_random_engine random_engine(random_device());
+  std::uniform_real_distribution<double> uniform_dist(0.0, 100.0);
+
+  const std::size_t sz = 100000;
+  std::vector<double> v;
+  v.reserve(sz);
+  for (std::size_t i = 0; i < sz; ++i) {
+    v.push_back(uniform_dist(random_engine));
+  }
+
+  sort_large(v);
+
+  return 0;
+}

examples/json/CMakeLists.txt

@@ -5,7 +5,7 @@ project(CPMJSONExample)
 # ---- Dependencies ----
 
 include(../../cmake/CPM.cmake)
-CPMAddPackage("gh:nlohmann/json@3.9.1")
+CPMAddPackage("gh:nlohmann/json@3.10.5")
 
 # ---- Executable ----
 

examples/linenoise/main.cpp

@@ -56,7 +56,7 @@ int main(int argc, char **argv) {
       int len = atoi(line + 11);
       linenoiseHistorySetMaxLen(len);
     } else if (line[0] == '/') {
-      printf("Unreconized command: %s\n", line);
+      printf("Unrecognized command: %s\n", line);
     }
     free(line);
   }

examples/range-v3/CMakeLists.txt

@@ -6,7 +6,7 @@ project(CPMRangev3Example)
 
 include(../../cmake/CPM.cmake)
 
-CPMAddPackage("gh:ericniebler/range-v3#0.11.0")
+CPMAddPackage("gh:ericniebler/range-v3#0.12.0")
 
 # ---- Executable ----
 

examples/simdjson/CMakeLists.txt

@@ -0,0 +1,14 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMSIMDJSONExample)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+CPMAddPackage("gh:simdjson/simdjson@3.5.0")
+
+# ---- Executable ----
+
+add_executable(CPMSIMDJSONExample main.cpp)
+target_compile_features(CPMSIMDJSONExample PRIVATE cxx_std_17)
+target_link_libraries(CPMSIMDJSONExample simdjson::simdjson)

examples/simdjson/main.cpp

@@ -0,0 +1,31 @@
+#include <iostream>
+
+#include "simdjson.h"
+using namespace simdjson;
+
+int main() {
+  ondemand::parser parser;
+  auto cars_json = R"( [
+    { "make": "Toyota", "model": "Camry",  "year": 2018, "tire_pressure": [ 40.1, 39.9, 37.7, 40.4 ] },
+    { "make": "Kia",    "model": "Soul",   "year": 2012, "tire_pressure": [ 30.1, 31.0, 28.6, 28.7 ] },
+    { "make": "Toyota", "model": "Tercel", "year": 1999, "tire_pressure": [ 29.8, 30.0, 30.2, 30.5 ] }
+  ] )"_padded;
+
+  // Iterating through an array of objects
+  for (ondemand::object car : parser.iterate(cars_json)) {
+    // Accessing a field by name
+    std::cout << "Make/Model: " << std::string_view(car["make"]) << "/"
+              << std::string_view(car["model"]) << std::endl;
+
+    // Casting a JSON element to an integer
+    uint64_t year = car["year"];
+    std::cout << "- This car is " << 2020 - year << " years old." << std::endl;
+
+    // Iterating through an array of floats
+    double total_tire_pressure = 0;
+    for (double tire_pressure : car["tire_pressure"]) {
+      total_tire_pressure += tire_pressure;
+    }
+    std::cout << "- Average tire pressure: " << (total_tire_pressure / 4) << std::endl;
+  }
+}

examples/sol2/CMakeLists.txt

@@ -8,36 +8,29 @@ include(../../cmake/CPM.cmake)
 
 CPMAddPackage(
   NAME lua
-  GIT_REPOSITORY https://github.com/lua/lua.git
+  GITHUB_REPOSITORY lua/lua
   VERSION 5.3.5
   DOWNLOAD_ONLY YES
 )
 
 if(lua_ADDED)
   # lua has no CMakeLists, so we create our own target
-
   file(GLOB lua_sources ${lua_SOURCE_DIR}/*.c)
   list(REMOVE_ITEM lua_sources "${lua_SOURCE_DIR}/lua.c" "${lua_SOURCE_DIR}/luac.c")
   add_library(lua STATIC ${lua_sources})
-
   target_include_directories(lua SYSTEM PUBLIC $<BUILD_INTERFACE:${lua_SOURCE_DIR}>)
 endif()
 
 CPMAddPackage(
   NAME sol2
-  URL https://github.com/ThePhD/sol2/archive/v3.0.2.zip
+  GITHUB_REPOSITORY ThePhD/sol2
-  VERSION 3.0.2
+  VERSION 3.3.0
-  DOWNLOAD_ONLY YES
+  # fix for clang 18.1.0, see https://github.com/ThePhD/sol2/issues/1581#issuecomment-2103463524
+  PATCHES fix_for_clang.patch
 )
 
-if(sol2_ADDED)
-  add_library(sol2 INTERFACE IMPORTED)
-  target_include_directories(sol2 SYSTEM INTERFACE ${sol2_SOURCE_DIR}/include)
-  target_link_libraries(sol2 INTERFACE lua)
-endif()
-
 # ---- Executable ----
 
 add_executable(CPMSol2Example main.cpp)
 target_compile_features(CPMSol2Example PRIVATE cxx_std_17)
-target_link_libraries(CPMSol2Example sol2)
+target_link_libraries(CPMSol2Example sol2 lua)

examples/sol2/fix_for_clang.patch

@@ -0,0 +1,18 @@
+diff -u a/include/sol/function_types_stateless.hpp b/include/types/function_types_stateless.hpp
+--- a/include/sol/function_types_stateless.hpp
++++ b/include/sol/function_types_stateless.hpp
+@@ -322,7 +322,13 @@ namespace sol { namespace function_detail {
+ 		}
+ 
+ 		template <bool is_yielding, bool no_trampoline>
+-		static int call(lua_State* L) noexcept(std::is_nothrow_copy_assignable_v<T>) {
++		static int call(lua_State* L)
++#if SOL_IS_ON(SOL_COMPILER_CLANG)
++		// apparent regression in clang 18 - llvm/llvm-project#91362
++#else
++			noexcept(std::is_nothrow_copy_assignable_v<T>)
++#endif
++		{
+ 			int nr;
+ 			if constexpr (no_trampoline) {
+ 				nr = real_call(L);

examples/spdlog/CMakeLists.txt

@@ -8,6 +8,20 @@ include(../../cmake/CPM.cmake)
 
 CPMAddPackage("gh:gabime/spdlog@1.8.2")
 
+# spdlog uses fmt and bundles that dependency. If you want to use fmt in your project as well, you
+# can let spdlog reuse fmt from CPM.cmake like this:
+#
+# cmake-format: off
+#
+# CPMAddPackage("gh:fmtlib/fmt#7.1.3") 
+# CPMAddPackage(
+#   GITHUB_REPOSITORY gabime/spdlog 
+#   VERSION 1.8.2 
+#   OPTIONS "SPDLOG_FMT_EXTERNAL 1" 
+# )
+#
+# cmake-format: on
+
 # ---- Executable ----
 
 add_executable(CPMSpdlogExample main.cpp)

examples/xxHash/CMakeLists.txt

@@ -0,0 +1,20 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMxxHashExample)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+
+CPMAddPackage(
+  GITHUB_REPOSITORY Cyan4973/xxHash
+  GIT_TAG v0.8.2
+  OPTIONS "XXHASH_BUILD_ENABLE_INLINE_API OFF" "XXHASH_BUILD_XXHSUM OFF"
+  SOURCE_SUBDIR cmake_unofficial
+)
+
+# ---- Executable ----
+
+add_executable(CPMxxHashExample main.cpp)
+target_compile_features(CPMxxHashExample PRIVATE cxx_std_17)
+target_link_libraries(CPMxxHashExample xxHash::xxhash)

examples/xxHash/main.cpp

@@ -0,0 +1,12 @@
+#include <xxh3.h>
+
+#include <iostream>
+
+int main() {
+  std::string example = "Hello World!";
+  XXH64_hash_t hash = XXH3_64bits(example.data(), example.size());
+
+  std::cout << "Hash: " << hash << std::endl;
+
+  return 0;
+}

test/CMakeLists.txt

@@ -14,3 +14,5 @@ foreach(test ${tests})
 endforeach()
 
 add_custom_target(test-verbose COMMAND ${CMAKE_CTEST_COMMAND} -C Debug --verbose)
+
+add_subdirectory(style)

test/integration/.gitignore

@@ -0,0 +1,2 @@
+# Use this to have a local integration test which is for personal experiments
+test_local.rb

test/integration/README.md

@@ -0,0 +1,44 @@
+# CPM.cmake Integration Tests
+
+The integration tests of CPM.cmake are written in Ruby. They use a custom integration test framework which extends the [Test::Unit](https://www.rubydoc.info/github/test-unit/test-unit/Test/Unit) library.
+
+They require Ruby 2.7.0 or later.
+
+## Running tests
+
+To run all tests from the repo root execute:
+
+```
+$ ruby test/integration/runner.rb
+```
+
+The runner will run all tests and generate a report of the execution.
+
+The current working directory doesn't matter. If you are in `<repo-root>/test/integration`, you can run simply `$ ruby runner.rb`.
+
+You can execute with `--help` (`$ ruby runner.rb --help`) to see various configuration options of the runner like running individual tests or test cases, or ones that match a regex.
+
+The tests themselves are situated in the Ruby scripts prefixed with `test_`. `<repo-root>/test/integration/test_*`. You can also run an individual test script. For example to only run the **basics** test case, you can execute `$ ruby test_basics.rb`
+
+The tests generate CMake scripts and execute CMake and build toolchains. By default they do this in a directory they generate in your temp path (`/tmp/cpm-test/` on Linux). You can configure the working directory of the tests with an environment variable `CPM_INTEGRATION_TEST_DIR`. For example `$ CPM_INTEGRATION_TEST_DIR=~/mycpmtest; ruby runner.rb`
+
+## Writing tests
+
+Writing tests makes use of the custom integration test framework in `lib.rb`. It is a relatively small extension of Ruby's Test::Unit library.
+
+### The Gist
+
+* Tests cases are Ruby scripts in this directory. The file names must be prefixed with `test_`
+* The script should `require_relative './lib'` to allow for individual execution (or else if will only be executable from the runner)
+* A test case file should contain a single class which inherits from `IntegrationTest`. It *can* contain multiple classes, but that's bad practice as it makes individual execution harder and implies a dependency between the classes.
+* There should be no dependency between the test scripts. Each should be executable individually and the order in which multiple ones are executed mustn't matter.
+* The class should contain methods, also prefixed with `test_` which will be executed by the framework. In most cases there would be a single test method per class.
+* In case there are multiple test methods, they will be executed in the order in which they are defined.
+* The test methods should contain assertions which check for the expected state of things at various points of the test's execution.
+
+### More
+
+* [A basic tutorial on writing integration tests.](tutorial.md)
+* [A brief reference of the integration test framework](reference.md)
+* Make sure you're familiar with the [idiosyncrasies](idiosyncrasies.md) of writing integration tests
+* [Some tips and tricks](tips.md)

test/integration/idiosyncrasies.md

@@ -0,0 +1,98 @@
+# Notable Idiosyncrasies When Writing Integration Tests
+
+As an integration test framework based on a unit test framework the one created for CPM.cmake suffers from several idiosyncrasies. Make sure you familiarize yourself with them before writing integration tests.
+
+## No shared instance variables between methods
+
+The runner will create an instance of the test class for each test method. This means that instance variables defined in a test method, *will not* be visible in another. For example:
+
+```ruby
+class MyTest < IntegrationTest
+  def test_something
+    @x = 123
+    assert_equal 123, @x # Pass. @x is 123
+  end
+  def test_something_else
+    assert_equal 123, @x # Fail! @x would be nil here
+  end
+end
+```
+
+There are hacks around sharing Ruby state between methods, but we choose not to use them. If you want to initialize something for all test methods, use `setup`.
+
+```ruby
+class MyTest < IntegrationTest
+  def setup
+    @x = 123
+  end
+  def test_something
+    assert_equal 123, @x # Pass. @x is 123 thanks to setup
+  end
+  def test_something_else
+    assert_equal 123, @x # Pass. @x is 123 thanks to setup
+  end
+end
+```
+
+## `IntegrationTest` makes use of `Test::Unit::TestCase#cleanup`
+
+After each test method the `cleanup` method is called thanks to Test::Unit. If you require the use of `cleanup` in your own tests, make sure you call `super` to also run `IntegrationTest#cleanup`.
+
+```ruby
+class MyTest < IntegrationTest
+  def cleanup
+    super
+    my_cleanup
+  end
+  # ...
+end
+```
+
+## It's better to have assertions in test methods as opposed to helper methods
+
+Test::Unit will display a helpful message if an assertion has failed. It will also include the line of code in the test method which caused the failure. However if an assertion is not in the test method, it will display the line which calls the method in which it is. So, please try, to have most assertions in test methods (though we acknowledge that in certain cases this is not practical). For example, if you only require scopes, try using lambdas.
+
+Instead of this:
+
+```ruby
+class MyTest < IntegrationTest
+  def test_something
+    do_a
+    do_b
+    do_c
+  end
+  def do_a
+    # ...
+  end
+  def do_b
+    # ...
+    assert false # will display failed line as "do_b"
+  end
+  def do_c
+    # ...
+  end
+end
+```
+
+...write this:
+
+```ruby
+class MyTest < IntegrationTest
+  def test_something
+    do_a = -> {
+      # ...
+    }
+    do_b = -> {
+      # ...
+      assert false # will display failed line as "assert false"
+    }
+    do_c = -> {
+      # ...
+    }
+
+    do_a.()
+    do_b.()
+    do_c.()
+  end
+end
+```

test/integration/lib.rb

@@ -0,0 +1,206 @@
+require 'fileutils'
+require 'open3'
+require 'tmpdir'
+require 'test/unit'
+
+module TestLib
+  TMP_DIR = File.expand_path(ENV['CPM_INTEGRATION_TEST_DIR'] || File.join(Dir.tmpdir, 'cpm-test', Time.now.strftime('%Y_%m_%d-%H_%M_%S')))
+  CPM_PATH = File.expand_path('../../cmake/CPM.cmake', __dir__)
+
+  TEMPLATES_DIR = File.expand_path('templates', __dir__)
+
+  # Environment variables which are read by cpm
+  CPM_ENV = %w(
+    CPM_USE_LOCAL_PACKAGES
+    CPM_LOCAL_PACKAGES_ONLY
+    CPM_DOWNLOAD_ALL
+    CPM_DONT_UPDATE_MODULE_PATH
+    CPM_DONT_CREATE_PACKAGE_LOCK
+    CPM_INCLUDE_ALL_IN_PACKAGE_LOCK
+    CPM_USE_NAMED_CACHE_DIRECTORIES
+    CPM_SOURCE_CACHE
+  )
+  def self.clear_env
+    CPM_ENV.each { ENV[_1] = nil }
+  end
+end
+
+puts "Warning: test directory '#{TestLib::TMP_DIR}' already exists" if File.exist?(TestLib::TMP_DIR)
+raise "Cannot find 'CPM.cmake' at '#{TestLib::CPM_PATH}'" if !File.file?(TestLib::CPM_PATH)
+
+puts "Running CPM.cmake integration tests"
+puts "Temp directory: '#{TestLib::TMP_DIR}'"
+
+# Clean all CPM-related env vars
+TestLib.clear_env
+
+class Project
+  def initialize(src_dir, bin_dir)
+    @src_dir = src_dir
+    @bin_dir = bin_dir
+  end
+
+  attr :src_dir, :bin_dir
+
+  def create_file(target_path, text, args = {})
+    target_path = File.join(@src_dir, target_path)
+
+    # tweak args
+    args[:cpm_path] = TestLib::CPM_PATH if !args[:cpm_path]
+    args[:packages] = [args[:package]] if args[:package] # if args contain package, create the array
+    args[:packages] = args[:packages].join("\n") if args[:packages] # join all packages if any
+
+    File.write target_path, text % args
+  end
+
+  def create_file_from_template(target_path, source_path, args = {})
+    source_path = File.join(@src_dir, source_path)
+    raise "#{source_path} doesn't exist" if !File.file?(source_path)
+    src_text = File.read source_path
+    create_file target_path, src_text, args
+  end
+
+  # common function to create ./CMakeLists.txt from ./lists.in.cmake
+  def create_lists_from_default_template(args = {})
+    create_file_from_template 'CMakeLists.txt', 'lists.in.cmake', args
+  end
+
+  CommandResult = Struct.new :out, :err, :status
+  def configure(extra_args = '')
+    CommandResult.new *Open3.capture3("cmake -S #{@src_dir} -B #{@bin_dir} #{extra_args}")
+  end
+  def build(extra_args = '')
+    CommandResult.new *Open3.capture3("cmake --build #{@bin_dir} #{extra_args}")
+  end
+
+  class CMakeCache
+    class Entry
+      def initialize(val, type, advanced, desc)
+        @val = val
+        @type = type
+        @advanced = advanced
+        @desc = desc
+      end
+      attr :val, :type, :advanced, :desc
+      alias_method :advanced?, :advanced
+      def inspect
+        "(#{val.inspect} #{type}" + (advanced? ? ' ADVANCED)' : ')')
+      end
+    end
+
+    Package = Struct.new(:ver, :src_dir, :bin_dir)
+
+    def self.from_dir(dir)
+      entries = {}
+      cur_desc = ''
+      file = File.join(dir, 'CMakeCache.txt')
+      return nil if !File.file?(file)
+      File.readlines(file).each { |line|
+        line.strip!
+        next if line.empty?
+        next if line.start_with? '#' # comment
+        if line.start_with? '//'
+          cur_desc += line[2..]
+        else
+          m = /(.+?)(-ADVANCED)?:([A-Z]+)=(.*)/.match(line)
+          raise "Error parsing '#{line}' in #{file}" if !m
+          entries[m[1]] = Entry.new(m[4], m[3], !!m[2], cur_desc)
+          cur_desc = ''
+        end
+      }
+      CMakeCache.new entries
+    end
+
+    def initialize(entries)
+      @entries = entries
+
+      package_list = self['CPM_PACKAGES']
+      @packages = if package_list
+        # collect package data
+        @packages = package_list.split(';').map { |name|
+          [name, Package.new(
+            self["CPM_PACKAGE_#{name}_VERSION"],
+            self["CPM_PACKAGE_#{name}_SOURCE_DIR"],
+            self["CPM_PACKAGE_#{name}_BINARY_DIR"]
+          )]
+        }.to_h
+      else
+        {}
+      end
+    end
+
+    attr :entries, :packages
+
+    def [](key)
+      e = @entries[key]
+      return nil if !e
+      e.val
+    end
+  end
+  def read_cache
+    CMakeCache.from_dir @bin_dir
+  end
+end
+
+class IntegrationTest < Test::Unit::TestCase
+  self.test_order = :defined # run tests in order of definition (as opposed to alphabetical)
+
+  def cleanup
+    # Clear cpm-related env vars which may have been set by the test
+    TestLib.clear_env
+  end
+
+  # extra assertions
+
+  def assert_success(res)
+    msg = build_message(nil, "command status was expected to be a success, but failed with code <?> and STDERR:\n\n#{res.err}", res.status.to_i)
+    assert_block(msg) { res.status.success? }
+  end
+
+  def assert_failure(res)
+    msg = build_message(nil, "command status was expected to be a failure, but succeeded")
+    assert_block(msg) { !res.status.success? }
+  end
+
+  def assert_same_path(a, b)
+    msg = build_message(nil, "<?> expected but was\n<?>", a, b)
+    assert_block(msg) { File.identical? a, b }
+  end
+
+  # utils
+  class << self
+    def startup
+      @@test_dir = File.join(TestLib::TMP_DIR, self.name.
+        # to-underscore conversion from Rails
+        gsub(/::/, '/').
+        gsub(/([A-Z]+)([A-Z][a-z])/,'\1_\2').
+        gsub(/([a-z\d])([A-Z])/,'\1_\2').
+        tr("-", "_").
+        downcase
+      )
+    end
+  end
+
+  def cur_test_dir
+    @@test_dir
+  end
+
+  def make_project(name: nil, from_template: nil)
+    test_name = local_name
+    test_name = test_name[5..] if test_name.start_with?('test_')
+
+    base = File.join(cur_test_dir, test_name)
+    base += "-#{name}" if name
+    src_dir = base + '-src'
+
+    FileUtils.mkdir_p src_dir
+
+    if from_template
+      from_template = File.join(TestLib::TEMPLATES_DIR, from_template)
+      raise "#{from_template} is not a directory" if !File.directory?(from_template)
+      FileUtils.copy_entry from_template, src_dir
+    end
+
+    Project.new src_dir, base + '-bin'
+  end
+end

test/integration/reference.md

@@ -0,0 +1,66 @@
+# Integration Test Framework Reference
+
+## `TestLib`
+
+A module for the framework. Provides global data and functionality. For ease of use the utility classes are *not* in this module.
+
+Provides:
+
+* `TMP_DIR` - the temporary directory for the current test run
+* `CPM_PATH` - path to CPM.cmake. The thing that is being tested
+* `TEMPLATES_DIR` - path to integration test templates
+* `CPM_ENV` - an array of the names of all environment variables, which CPM.cmake may read
+* `.clear_env` - a function to clear all aforementioned environment variables
+
+## `Project`
+
+A helper class to manage a CMake project.
+
+Provides:
+
+* `#initialize(src_dir, bin_dir)` - create a project with a given source and binary directory
+* `#src_dir`, `#bin_dir` - get project directories
+* `#create_file(target_path, text, args = {})` - create a file in the project's source directory with a given test. The `args` hash is used to interpolate markup in the text string.
+    * Will set `:cpm_path` in `args` to `TestLib::CPM_PATH` if not already present.
+    * If `:package` is present it will be added to the array `:packages`
+    * Will convert `:packages` form an array to a string
+* `#create_file_from_template(target_path, source_path, args = {})` - create a file in the project source directory, based on another file in the project source directory. The contents of the file at `source_path` will be read and used in `create_file`
+* `#create_lists_from_default_template(args = {})` - same as `create_file_from_template('CMakeLists.txt', 'lists.in.cmake', args)`
+* `::CommandResult` - a struct of:
+    * `out` - the standard output from a command execution
+    * `err` - the standard error output from the execution
+    * `status` - the [`Process::Status`](https://ruby-doc.org/core-2.7.0/Process/Status.html) of the execution
+* `#configure(extra_args = '') => CommandResult` - configure the project with optional extra args to CMake
+* `#build(extra_args = '') => CommandResult` - build the project with optional extra args to CMake
+* `::CMakeCache` - a helper class with the contents of a CMakeCache.txt. Provides:
+    * `::Entry` - a CMake cache entry of:
+        * `val` - the value as string
+        * `type` - the type as string
+        * `advanced?` - whether the entry is an advanced option
+        * `desc` - the description of the entry (can be an empty string)
+    * `::Package` - the CMake cache for a CPM.cmake package. A struct of:
+        * `ver` - the version as string
+        * `src_dir`, `bin_dir` - the source and binary directories of the package
+    * `.from_dir(dir)` - create an instance of `CMakeCache` from `<dir>/CMakeLists.txt`
+    * `#initialize(entries)` - create a cache from a hash of entries by name. Will populate packages.
+    * `#entries => {String => Entry}` - the entries of the cache
+    * `#packages => {String => Package}` - CPM.cmake packages by name found in the cache
+    * `#[](key) => String` - an entry value from an entry name. Created because the value is expected to be needed much more frequently than the entire entry data. To get a full entry use `cache.entries['name']`.
+* `read_cache => CMakeCache` - reads the CMake cache in the binary directory of the project and returns it as a `CMakeCache` instance
+
+## `IntegrationTest`
+
+The class which must be a parent of all integration test case classes. It itself extends `Test::Unit::TestCase` with:
+
+### Assertions
+
+* `assert_success(res)` - assert that an instance of `Project::CommandResult` is a success
+* `assert_same_path(a, b)` - assert that two strings represent the same path. For example on Windows `c:\foo` and `C:\Foo` do.
+
+### Utils
+
+* `cur_test_dir` - the directory of the current test case. A subdirectory of `TestLib::TMP_DIR`
+* `make_project(name: nil, from_template: nil)` - create a project from a test method. Will create the project's source and binary directories as subdirectories of `cur_test_dir`.
+    * Optionally provide a name which will be concatenated to the project directory. This allows creating multiple projects in a test
+    * Optionally work with a template, in which case it will copy the contents of the template directory (one from `templates`) in the project's source directory.
+

test/integration/runner.rb

@@ -0,0 +1,4 @@
+require_relative './lib'
+
+exit Test::Unit::AutoRunner::run(true, __dir__)
+

test/integration/templates/no-deps/lists.in.cmake

@@ -0,0 +1,7 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(no-deps)
+
+include("%{cpm_path}")
+
+add_executable(no-deps main.c)

test/integration/templates/no-deps/main.c

@@ -0,0 +1,6 @@
+#include <stdio.h>
+
+int main() {
+  puts("Hello");
+  return 0;
+}

test/integration/templates/using-adder/lists.in.cmake

@@ -0,0 +1,13 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(using-adder)
+
+set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
+
+include("%{cpm_path}")
+
+%{packages}
+
+add_executable(using-adder using-adder.cpp)
+
+target_link_libraries(using-adder adder)

test/integration/templates/using-adder/using-adder.cpp

@@ -0,0 +1,8 @@
+#include <adder/adder.hpp>
+#include <cstdio>
+
+int main() {
+  int sum = adder::add(5, 3);
+  std::printf("%d\n", sum);
+  return 0;
+}

test/integration/templates/using-fibadder/lists.in.cmake

@@ -0,0 +1,13 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(using-fibadder)
+
+set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
+
+include("%{cpm_path}")
+
+%{packages}
+
+add_executable(using-fibadder using-fibadder.cpp)
+
+target_link_libraries(using-fibadder fibadder)

test/integration/templates/using-fibadder/using-fibadder.cpp

@@ -0,0 +1,8 @@
+#include <cstdio>
+#include <fibadder/fibadder.hpp>
+
+int main() {
+  int sum = fibadder::fibadd(6, 7);
+  std::printf("%d\n", sum);
+  return 0;
+}

test/integration/templates/using-patch-adder/lists.in.cmake

@@ -0,0 +1,13 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(using-patch-adder)
+
+set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
+
+include("%{cpm_path}")
+
+%{packages}
+
+add_executable(using-patch-adder using-patch-adder.cpp)
+
+target_link_libraries(using-patch-adder adder)

test/integration/templates/using-patch-adder/patches/001-test_patches_command.patch

@@ -0,0 +1,12 @@
+diff --git a/code/adder/adder.hpp b/code/adder/adder.hpp
+index fdb9324..7c2fa00 100644
+--- a/code/adder/adder.hpp
++++ b/code/adder/adder.hpp
+@@ -1,6 +1,6 @@
+ #pragma once
+ 
+-namespace adder
++namespace patched
+ {
+ int add(int a, int b);
+ }

test/integration/templates/using-patch-adder/patches/002-test_patches_command.patch

@@ -0,0 +1,12 @@
+diff --git a/code/adder/adder.cpp b/code/adder/adder.cpp
+index fc6e767..44b1197 100644
+--- a/code/adder/adder.cpp
++++ b/code/adder/adder.cpp
+@@ -1,6 +1,6 @@
+ #include "adder.hpp"
+ 
+-namespace adder
++namespace patched
+ {
+ int add(int a, int b)
+ {

test/integration/templates/using-patch-adder/using-patch-adder.cpp

@@ -0,0 +1,8 @@
+#include <adder/adder.hpp>
+#include <cstdio>
+
+int main() {
+  int sum = patched::add(5, 3);
+  std::printf("%d\n", sum);
+  return 0;
+}

test/integration/test_basics.rb

@@ -0,0 +1,58 @@
+require_relative './lib'
+
+# Tests of cpm caches and vars when no packages are used
+
+class Basics < IntegrationTest
+  # Test cpm caches with no cpm-related env vars
+  def test_cpm_default
+    prj = make_project from_template: 'no-deps'
+    prj.create_lists_from_default_template
+    assert_success prj.configure
+
+    @cache = prj.read_cache
+
+    assert_empty @cache.packages
+
+    assert_same_path TestLib::CPM_PATH, check_and_get('CPM_FILE')
+    assert_same_path File.dirname(TestLib::CPM_PATH), check_and_get('CPM_DIRECTORY')
+
+    assert_equal 'OFF', check_and_get('CPM_DRY_RUN')
+    assert_equal 'CPM:', check_and_get('CPM_INDENT')
+    assert_equal '1.0.0-development-version', check_and_get('CPM_VERSION')
+
+    assert_equal 'OFF', check_and_get('CPM_SOURCE_CACHE', 'PATH')
+    assert_equal 'OFF', check_and_get('CPM_DOWNLOAD_ALL', 'BOOL')
+    assert_equal 'OFF', check_and_get('CPM_LOCAL_PACKAGES_ONLY', 'BOOL')
+    assert_equal 'OFF', check_and_get('CPM_USE_LOCAL_PACKAGES', 'BOOL')
+    assert_equal 'OFF', check_and_get('CPM_USE_NAMED_CACHE_DIRECTORIES', 'BOOL')
+
+    assert_equal 'OFF', check_and_get('CPM_DONT_CREATE_PACKAGE_LOCK', 'BOOL')
+    assert_equal 'OFF', check_and_get('CPM_INCLUDE_ALL_IN_PACKAGE_LOCK', 'BOOL')
+    assert_same_path File.join(prj.bin_dir, 'cpm-package-lock.cmake'), check_and_get('CPM_PACKAGE_LOCK_FILE')
+
+    assert_equal 'OFF', check_and_get('CPM_DONT_UPDATE_MODULE_PATH', 'BOOL')
+    if @cache.entries['CMAKE_FIND_PACKAGE_REDIRECTS_DIR'].nil?
+      assert_same_path File.join(prj.bin_dir, 'CPM_modules'), check_and_get('CPM_MODULE_PATH')
+    end
+  end
+
+  # Test when env CPM_SOURCE_CACHE is set
+  def test_env_cpm_source_cache
+    ENV['CPM_SOURCE_CACHE'] = cur_test_dir
+
+    prj = make_project from_template: 'no-deps'
+    prj.create_lists_from_default_template
+    assert_success prj.configure
+
+    @cache = prj.read_cache
+
+    assert_equal cur_test_dir, check_and_get('CPM_SOURCE_CACHE', 'PATH')
+  end
+
+  def check_and_get(key, type = 'INTERNAL')
+    e = @cache.entries[key]
+    assert_not_nil e, key
+    assert_equal type, e.type, key
+    e.val
+  end
+end

test/integration/test_download_command.rb

@@ -0,0 +1,25 @@
+require_relative './lib'
+
+# Tests using a multi-argumenet download command to fetch a dependency
+
+class DownloadCommand < IntegrationTest
+
+  def test_fetch_dependency_using_download_command
+    prj = make_project from_template: 'using-adder'
+
+    prj.create_lists_from_default_template package: <<~PACK
+      set(DOWNLOAD_DIR ${CMAKE_BINARY_DIR}/_deps/testpack-adder-src)
+      CPMAddPackage(
+        NAME testpack-adder
+        SOURCE_DIR ${DOWNLOAD_DIR}
+        DOWNLOAD_COMMAND git clone --depth 1 --branch v1.0.0 https://github.com/cpm-cmake/testpack-adder.git ${DOWNLOAD_DIR}
+        OPTIONS "ADDER_BUILD_TESTS OFF"
+      )
+    PACK
+
+    # configure with unpopulated cache
+    assert_success prj.configure
+    assert_success prj.build
+  end
+
+end

test/integration/test_fetchcontent_compatibility.rb

@@ -0,0 +1,43 @@
+require_relative './lib'
+
+# Tests FetchContent overriding with CPM
+
+class FetchContentCompatibility < IntegrationTest
+  def setup
+    @cache_dir = File.join(cur_test_dir, 'cpmcache')
+    ENV['CPM_SOURCE_CACHE'] = @cache_dir
+  end
+
+  def test_add_dependency_cpm_and_fetchcontent
+    prj = make_project from_template: 'using-adder'
+
+    prj.create_lists_from_default_template package: <<~PACK
+      CPMAddPackage(
+        NAME testpack-adder
+        GITHUB_REPOSITORY cpm-cmake/testpack-adder
+        VERSION 1.0.0
+        OPTIONS "ADDER_BUILD_TESTS OFF"
+      )
+
+      # should have no effect, as we added the dependency using CPM
+      FetchContent_Declare(
+        testpack-adder
+        GIT_REPOSITORY https://github.com/cpm-cmake/testpack-adder
+        GIT_TAG v1.0.0
+      )
+      FetchContent_MakeAvailable(testpack-adder)
+    PACK
+
+    # configure with unpopulated cache
+    assert_success prj.configure
+    assert_success prj.build
+
+    # cache is populated
+    assert_true File.exist?(File.join(@cache_dir, "testpack-adder"))
+
+    # configure with populated cache
+    assert_success prj.configure
+    assert_success prj.build
+  end
+
+end

test/integration/test_parallelism.rb

@@ -0,0 +1,21 @@
+require_relative './lib'
+
+class Parallelism < IntegrationTest
+  def setup
+    @cache_dir = File.join(cur_test_dir, 'cpmcache')
+    ENV['CPM_SOURCE_CACHE'] = @cache_dir
+  end
+
+  def test_populate_cache_in_parallel
+    4.times.map { |i|
+      prj = make_project name: i.to_s, from_template: 'using-fibadder'
+      prj.create_lists_from_default_template package: 'CPMAddPackage("gh:cpm-cmake/testpack-fibadder@1.0.0")'
+      prj
+    }.map { |prj|
+      Thread.new do
+        assert_success prj.configure
+        assert_success prj.build
+      end
+    }.map(&:join)
+  end
+end

test/integration/test_patches_command.rb

@@ -0,0 +1,27 @@
+require_relative './lib'
+
+# Tests using a multi-argumenet PATCHES command to fetch and modify a dependency
+
+class DownloadCommand < IntegrationTest
+
+  def test_fetch_dependency_using_download_command
+    prj = make_project from_template: 'using-patch-adder'
+
+    prj.create_lists_from_default_template package: <<~PACK
+      set(DOWNLOAD_DIR ${CMAKE_BINARY_DIR}/_deps/testpack-adder-src)
+      CPMAddPackage(
+        NAME testpack-adder
+        DOWNLOAD_COMMAND git clone --depth 1 --branch v1.0.0 https://github.com/cpm-cmake/testpack-adder.git ${DOWNLOAD_DIR}
+        OPTIONS "ADDER_BUILD_TESTS OFF" "ADDER_BUILD_EXAMPLES OFF"
+        PATCHES
+          patches/001-test_patches_command.patch
+          patches/002-test_patches_command.patch
+      )
+    PACK
+
+    # configure with unpopulated cache
+    assert_success prj.configure
+    assert_success prj.build
+  end
+
+end

test/integration/test_relative_urls.rb

@@ -0,0 +1,17 @@
+require_relative './lib'
+
+class RelativeURLs < IntegrationTest
+  def setup
+    # relative URLs were introduced in CMake 3.27
+    @relative_urls_supported = (!ENV['CMAKE_VERSION']) || (Gem::Version.new(ENV['CMAKE_VERSION']) >= Gem::Version.new('3.27'))
+  end
+
+  def test_add_project_with_relative_urls
+    omit_if !@relative_urls_supported do
+      prj = make_project from_template: 'using-fibadder'
+      prj.create_lists_from_default_template package: 'CPMAddPackage("gh:cpm-cmake/testpack-fibadder@1.1.0-relative-urls")'
+      assert_success prj.configure
+      assert_success prj.build
+    end
+  end
+end

test/integration/test_remove_source_dir.rb

@@ -0,0 +1,36 @@
+require_relative './lib'
+
+class RemoveSourceDir < IntegrationTest
+  def test_remove_source_dir
+    prj = make_project from_template: 'using-adder'
+
+    prj.create_lists_from_default_template package: <<~PACK
+      CPMAddPackage(
+        NAME testpack-adder
+        GITHUB_REPOSITORY cpm-cmake/testpack-adder
+        VERSION 1.0.0
+        OPTIONS "ADDER_BUILD_TESTS OFF"
+        SOURCE_DIR testpack-adder
+      )
+    PACK
+
+    # configure and build
+    assert_success prj.configure
+    assert_success prj.build
+
+    # source_dir is populated
+    assert_true File.exist?(File.join(prj.bin_dir, 'testpack-adder'))
+
+    # source_dir is deleted by user
+    FileUtils.remove_dir(File.join(prj.bin_dir, 'testpack-adder'), true)
+    assert_false File.exist?(File.join(prj.bin_dir, 'testpack-adder'))
+
+    # configure and build with missing source_dir to fetch new content
+    assert_success prj.configure
+    assert_success prj.build
+
+    # source_dir is populated
+    assert_true File.exist?(File.join(prj.bin_dir, 'testpack-adder'))
+  end
+
+end

test/integration/test_shorthand_syntax.rb

@@ -0,0 +1,86 @@
+require_relative './lib'
+
+class TestShorthandSyntax < IntegrationTest
+
+  def get_project_binaries prj
+    exe_dir = File.join(prj.bin_dir, 'bin')
+    assert File.directory? exe_dir
+    return Dir[exe_dir + '/**/*'].filter {
+        # on multi-configuration generators (like Visual Studio) the executables will be in bin/<Config>
+        # also filter-out other artifacts like .pdb or .dsym
+        !File.directory?(_1) && File.stat(_1).executable?
+      }.map {
+        # remove .exe extension if any (there will be one on Windows)
+        File.basename(_1, '.exe')
+      }.sort
+  end
+
+  def test_create_with_commit_sha
+    prj = make_project from_template: 'using-adder'
+    prj.create_lists_from_default_template package:
+    'CPMAddPackage("gh:cpm-cmake/testpack-adder#cad1cd4b4cdf957c5b59e30bc9a1dd200dbfc716")'
+    assert_success prj.configure
+
+    cache = prj.read_cache
+    assert_equal 1, cache.packages.size
+    assert_equal '0', cache.packages['testpack-adder'].ver
+
+    assert_success prj.build
+    exes = get_project_binaries prj
+    # No adder projects were built as EXCLUDE_FROM_ALL is implicitly set
+    assert_equal ['using-adder'], exes
+  end
+
+  def test_create_with_version
+    prj = make_project from_template: 'using-adder'
+    prj.create_lists_from_default_template package:
+    'CPMAddPackage("gh:cpm-cmake/testpack-adder@1.0.0")'
+    assert_success prj.configure
+
+    cache = prj.read_cache
+    assert_equal 1, cache.packages.size
+    assert_equal '1.0.0', cache.packages['testpack-adder'].ver
+
+    assert_success prj.build
+    exes = get_project_binaries prj
+    assert_equal ['using-adder'], exes
+  end
+
+  def test_create_with_all
+    prj = make_project from_template: 'using-adder'
+    prj.create_lists_from_default_template package:
+    'CPMAddPackage(
+      URI "gh:cpm-cmake/testpack-adder@1.0.0"
+      EXCLUDE_FROM_ALL false
+    )'
+    assert_success prj.configure
+
+    cache = prj.read_cache
+    assert_equal cache.packages.size, 1
+    assert_equal cache.packages['testpack-adder'].ver, '1.0.0'
+    
+    assert_success prj.build
+    exes = get_project_binaries prj
+    assert_equal exes, ['simple', 'test-adding', 'using-adder']
+  end
+
+  def test_create_with_tests_but_without_examples
+    prj = make_project from_template: 'using-adder'
+    prj.create_lists_from_default_template package:
+    'CPMAddPackage(
+      URI "gh:cpm-cmake/testpack-adder@1.0.0"
+      OPTIONS "ADDER_BUILD_EXAMPLES OFF" "ADDER_BUILD_TESTS TRUE"
+      EXCLUDE_FROM_ALL false
+    )'
+    assert_success prj.configure
+
+    cache = prj.read_cache
+    assert_equal cache.packages.size, 1
+    assert_equal cache.packages['testpack-adder'].ver, '1.0.0'
+    
+    assert_success prj.build
+    exes = get_project_binaries prj
+    assert_equal exes, ['test-adding', 'using-adder']
+  end
+
+end

test/integration/test_simple.rb

@@ -0,0 +1,91 @@
+require_relative './lib'
+
+class Simple < IntegrationTest
+  ADDER_PACKAGE_NAME = 'testpack-adder'
+
+  def test_update_single_package
+    prj = make_project from_template: 'using-adder'
+    adder_cache0 = nil
+    adder_ver_file = nil
+
+    create_with_commit_sha = -> {
+      prj.create_lists_from_default_template package:
+        'CPMAddPackage("gh:cpm-cmake/testpack-adder#cad1cd4b4cdf957c5b59e30bc9a1dd200dbfc716")'
+      assert_success prj.configure
+
+      cache = prj.read_cache
+      assert_equal 1, cache.packages.size
+
+      adder_cache = cache.packages[ADDER_PACKAGE_NAME]
+      assert_not_nil adder_cache
+      assert_equal '0', adder_cache.ver
+      assert File.directory? adder_cache.src_dir
+      assert File.directory? adder_cache.bin_dir
+
+      adder_ver_file = File.join(adder_cache.src_dir, 'version')
+      assert File.file? adder_ver_file
+      assert_equal 'initial', File.read(adder_ver_file).strip
+
+      # calculated adder values
+      assert_equal 'ON', cache['ADDER_BUILD_EXAMPLES']
+      assert_equal 'ON', cache['ADDER_BUILD_TESTS']
+      assert_equal adder_cache.src_dir, cache['adder_SOURCE_DIR']
+      assert_equal adder_cache.bin_dir, cache['adder_BINARY_DIR']
+
+      # store for future comparisons
+      adder_cache0 = adder_cache
+    }
+    update_to_version_1 = -> {
+      prj.create_lists_from_default_template package:
+        'CPMAddPackage("gh:cpm-cmake/testpack-adder@1.0.0")'
+      assert_success prj.configure
+
+      cache = prj.read_cache
+      assert_equal 1, cache.packages.size
+
+      adder_cache = cache.packages[ADDER_PACKAGE_NAME]
+      assert_not_nil adder_cache
+      assert_equal '1.0.0', adder_cache.ver
+
+      # dirs shouldn't have changed
+      assert_equal adder_cache0.src_dir, adder_cache.src_dir
+      assert_equal adder_cache0.bin_dir, adder_cache.bin_dir
+
+      assert_equal '1.0.0', File.read(adder_ver_file).strip
+    }
+    update_with_option_off_and_build = -> {
+      prj.create_lists_from_default_template package: <<~PACK
+        CPMAddPackage(
+          NAME testpack-adder
+          GITHUB_REPOSITORY cpm-cmake/testpack-adder
+          VERSION 1.0.0
+          OPTIONS "ADDER_BUILD_TESTS OFF"
+        )
+      PACK
+      assert_success prj.configure
+      assert_success prj.build
+
+      exe_dir = File.join(prj.bin_dir, 'bin')
+      assert File.directory? exe_dir
+
+      exes = Dir[exe_dir + '/**/*'].filter {
+        # on multi-configuration generators (like Visual Studio) the executables will be in bin/<Config>
+        # also filter-out other artifacts like .pdb or .dsym
+        !File.directory?(_1) && File.stat(_1).executable?
+      }.map {
+        # remove .exe extension if any (there will be one on Windows)
+        File.basename(_1, '.exe')
+      }.sort
+
+      # we should end up with two executables
+      # * simple - the simple example from adder
+      # * using-adder - for this project
+      # ...and notably no test for adder, which must be disabled from the option override from above
+      assert_equal ['simple', 'using-adder'], exes
+    }
+
+    create_with_commit_sha.()
+    update_to_version_1.()
+    update_with_option_off_and_build.()
+  end
+end

test/integration/test_source_cache.rb

@@ -0,0 +1,91 @@
+require_relative './lib'
+
+# Tests with source cache
+
+class SourceCache < IntegrationTest
+  def setup
+    @cache_dir = File.join(cur_test_dir, 'cpmcache')
+    ENV['CPM_SOURCE_CACHE'] = @cache_dir
+  end
+
+  def test_add_remove_dependency
+    prj = make_project from_template: 'using-fibadder'
+
+    ###################################
+    # create
+    prj.create_lists_from_default_template package: 'CPMAddPackage("gh:cpm-cmake/testpack-fibadder@1.0.0")'
+    assert_success prj.configure
+
+    @cache = prj.read_cache
+
+    # fibadder - adder
+    #          \ fibonacci - Format
+    assert_equal 4, @cache.packages.size
+
+    check_package_cache 'testpack-fibadder', '1.0.0', '6a17d24c95c44a169ff8ba173f52876a2ba3d137'
+    check_package_cache 'testpack-adder', '1.0.0', '1a4c153849d8e0cf9a3a245e5f6ab6e4722d8995'
+    check_package_cache 'testpack-fibonacci', '2.0', '332c789cb09b8c2f92342dfb874c82bec643daf6'
+    check_package_cache 'Format.cmake', '1.0', 'c5897bd28c5032d45f7f669c8fb470790d2ae156'
+
+    ###################################
+    # add one package with a newer version
+    prj.create_lists_from_default_template packages: [
+      'CPMAddPackage("gh:cpm-cmake/testpack-adder@1.0.1")',
+      'CPMAddPackage("gh:cpm-cmake/testpack-fibadder@1.0.0")',
+    ]
+    assert_success prj.configure
+
+    @cache = prj.read_cache
+    assert_equal 4, @cache.packages.size
+
+    check_package_cache 'testpack-fibadder', '1.0.0', '6a17d24c95c44a169ff8ba173f52876a2ba3d137'
+    check_package_cache 'testpack-adder', '1.0.1', '84eb33c1b8db880083cefc2adf4dc3f04778cd44'
+    check_package_cache 'testpack-fibonacci', '2.0', '332c789cb09b8c2f92342dfb874c82bec643daf6'
+    check_package_cache 'Format.cmake', '1.0', 'c5897bd28c5032d45f7f669c8fb470790d2ae156'
+  end
+
+  def test_second_project
+    prj = make_project from_template: 'using-fibadder'
+    prj.create_lists_from_default_template package: 'CPMAddPackage("gh:cpm-cmake/testpack-fibadder@1.1.0")'
+    assert_success prj.configure
+
+    @cache = prj.read_cache
+
+    # fibadder - adder
+    #          \ fibonacci - Format
+    assert_equal 4, @cache.packages.size
+
+    check_package_cache 'testpack-fibadder', '1.1.0', '603d79d88d7230cc749460a0f476df862aa70ead'
+    check_package_cache 'testpack-adder', '1.0.1', '84eb33c1b8db880083cefc2adf4dc3f04778cd44'
+    check_package_cache 'testpack-fibonacci', '2.0', '332c789cb09b8c2f92342dfb874c82bec643daf6'
+    check_package_cache 'Format.cmake', '1.0', 'c5897bd28c5032d45f7f669c8fb470790d2ae156'
+  end
+
+  def test_cache_dir_contents
+    num_subdirs = -> (name) { Dir["#{File.join(@cache_dir, name.downcase)}/*/"].size }
+    assert_equal 2, num_subdirs.('testpack-fibadder')
+    assert_equal 2, num_subdirs.('testpack-adder')
+    assert_equal 1, num_subdirs.('testpack-fibonacci')
+    assert_equal 1, num_subdirs.('Format.cmake')
+  end
+
+  def check_package_cache(name, ver, dir_sha1)
+    package = @cache.packages[name]
+    assert_not_nil package, name
+    assert_equal ver, package.ver
+    expected_parent_dir = File.join(@cache_dir, name.downcase)
+    assert package.src_dir.start_with?(expected_parent_dir), "#{package.src_dir} must be in #{expected_parent_dir}"
+
+    # The hash has been shortened by cpm_get_shortest_hash. The following
+    # should hold:
+    # - The short hash should be a prefix of the input hash
+    # - There should be a file ".../${short_hash}.hash" which matches the full hash
+    short_hash = File.basename(package.src_dir)
+    assert dir_sha1.start_with?(short_hash), "short_hash should be a prefix of dir_sha1"
+
+    # Check that the full hash is stored in the .hash file
+    hash_file = "#{package.src_dir}.hash"
+    assert File.exist?(hash_file), "Hash file #{hash_file} should exist"
+    assert_equal dir_sha1, File.read(hash_file), "Hash file should contain the full original hash"
+  end
+end

test/integration/test_system_warnings.rb

@@ -0,0 +1,57 @@
+require_relative './lib'
+
+class SystemWarnings < IntegrationTest
+  
+  def setup
+    # system is only supported for CMake >= 3.25 
+    @system_supported = (!ENV['CMAKE_VERSION']) || (Gem::Version.new(ENV['CMAKE_VERSION']) >= Gem::Version.new('3.25'))
+  end
+
+  def test_dependency_added_using_system
+    for use_system in [true, false] do
+      prj = make_project name: use_system ? "system" : "no_system", from_template: 'using-adder'
+      prj.create_lists_from_default_template package: <<~PACK
+        # this commit has a warning in a public header
+        CPMAddPackage(
+          NAME Adder
+          GITHUB_REPOSITORY cpm-cmake/testpack-adder
+          GIT_TAG v1.0.1-warnings
+          SYSTEM #{use_system ? "YES" : "NO"}
+        )
+        # all packages using `adder` will error on warnings
+        target_compile_options(adder INTERFACE
+          $<$<CXX_COMPILER_ID:MSVC>:/Wall /WX>
+          $<$<NOT:$<CXX_COMPILER_ID:MSVC>>:-Wall -Werror>
+        )
+      PACK
+
+      assert_success prj.configure
+      if use_system and @system_supported
+        assert_success prj.build
+      else
+        assert_failure prj.build
+      end
+    end
+  end
+  
+  def test_dependency_added_implicitly_using_system
+    prj = make_project from_template: 'using-adder'
+    prj.create_lists_from_default_template package: <<~PACK
+      # this commit has a warning in a public header
+      CPMAddPackage("gh:cpm-cmake/testpack-adder@1.0.1-warnings")
+      # all packages using `adder` will error on warnings
+      target_compile_options(adder INTERFACE
+        $<$<CXX_COMPILER_ID:MSVC>:/Wall /WX>
+        $<$<NOT:$<CXX_COMPILER_ID:MSVC>>:-Wall -Werror>
+      )
+    PACK
+
+    assert_success prj.configure
+    if @system_supported
+      assert_success prj.build
+    else
+      assert_failure prj.build
+    end
+  end
+
+end

test/integration/tips.md

@@ -0,0 +1,35 @@
+# Tips and Tricks
+
+## Playing and experimenting
+
+Create a file called `test_local.rb` in this directory to have an integration test which is for your personal experiments and just playing with the integration test framework. `test_local.rb` is gitignored.
+
+## Speeding-up development
+
+Running an integration test requires configuring directories with CMake which can be quite slow. To speed-up development of integration tests consider doing the following steps:
+
+**Work with standalone tests**
+
+Instead of starting the runner, run just your integration test (`$ ruby test_your_test.rb`). This won't burden the execution with the others.
+
+**Export the environment variable `CPM_INTEGRATION_TEST_DIR` to some local directory**
+
+By default the framework generates a new temporary directory for each test run. If you override the temp directory to a specific one, rerunning the tests will work with the binary directories from the previous run and will improve the performance considerably.
+
+*NOTE HOWEVER* that in certain cases this may not be an option. Some tests might assert that certain artifacts in the temporary directory are missing but upon rerunning in an existing directory they will be there causing the test to fail.
+
+*ALSO NOTE* that this may silently affect reruns based on CMake caches from previous runs. If your test fails in peculiar ways on reruns, try a clean run. Always do a clean run before declaring a test a success.
+
+**Set `CPM_SOURCE_CACHE` even if the test doesn't require it**
+
+This is not a option for tests which explicitly check that there is no source cache. However certain tests may be indiferent to this. For such cases in development, you can add a setup function in the lines of:
+
+```ruby
+def setup
+  ENV['CPM_SOURCE_CACHE'] = '/home/myself/.testcpmcache'
+end
+```
+
+Then the packages from your test will be cached and not redownloaded every time which is a dramatic improvement in performance.
+
+*NOTE HOWEVER* that this may introduce subtle bugs. Always test without this dev-only addition, before declaring a test a success.

test/integration/tutorial.md

@@ -0,0 +1,69 @@
+# Integration Test Tutorial
+
+Let's create an integration test which checks that CPM.cmake can make a specific package available.
+
+First we do some boilerplate.
+
+```ruby
+require_relative './lib'
+
+class MyTest < IntegrationTest
+  # test that CPM.cmake can make https://github.com/cpm-cmake/testpack-adder/ available as a package
+  def test_make_adder_available
+  end
+end
+```
+
+Now we have our test case class, and the single test method that we will require. Let's focus on the method's contents. The integration test framework provides us with a helper class, `Project`, which can be used for this scenario. A project has an associated pair of source and binary directories in the temporary directory and it provides methods to work with them.
+
+We start by creating the project:
+
+```ruby
+prj = make_project
+```
+
+`make_project` is method of IntegrationTest which generates a source and a binary directory for it based on the name of our test class and test method. The project doesn't contain anything yet, so let's create some source files:
+
+```ruby
+prj.create_file 'main.cpp', <<~SRC
+  #include <iostream>
+  #include <adder/adder.hpp>
+  int main() {
+      std::cout << adder::add(1, 2) << '\\n';
+      return 0;
+  }
+SRC
+prj.create_file 'CMakeLists.txt', <<~SRC
+  cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+  project(using-adder)
+  set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
+  include("%{cpm_path}")
+  CPMAddPackage("gh:cpm-cmake/testpack-adder@1.0.0")
+  add_executable(using-adder main.cpp)
+  target_link_libraries(using-adder adder)
+SRC
+```
+
+Note the line `include("%{cpm_path}")` when creating `CMakeLists.txt`. It contains a markup `%{cpm_path}`. `Project#create_file` will see such markups and substitute them with the appropriate values (in this case the path to CPM.cmake).
+
+Now that we have the two files we need it's time we configure our project. We can use the opportunity to assert that the configure is successful as we expect it to be.
+
+```ruby
+assert_success prj.configure
+```
+
+Now we can read the generated `CMakeCache.txt` and assert that certain values we expect are inside. `Project` provides a method for that: `read_cache`. It will return an instance of `Project::CMakeCache` which contains the data from the cache and provides additional helper functionalities. One of them is `packages`, which is a hash of the CPM.cmake packages in the cache with their versions, binary, source directories. So let's get the cache and assert that there is only one CPM.cmake package inside ant it has the version we expect.
+
+```ruby
+cache = prj.read_cache
+assert_equal 1, cache.packages.size
+assert_equal '1.0.0', cache.packages['testpack-adder'].ver
+```
+
+Finally let's assert that the project can be built. This would mean that CPM.cmake has made the package available to our test project and that it has the appropriate include directories and link libraries to make an executable out of `main.cpp`.
+
+```ruby
+assert_success prj.build
+```
+
+You can see the entire code for this tutorial in [tutorial.rb](tutorial.rb) in this directory.

test/integration/tutorial.rb

@@ -0,0 +1,37 @@
+# This file is intentionally not prefixed with test_
+# It is a tutorial for making integration tests and is not to be run from the runner
+require_relative './lib'
+
+class Tutorial < IntegrationTest
+  # test that CPM.cmake can make https://github.com/cpm-cmake/testpack-adder/ available as a package
+  def test_make_adder_available
+    prj = make_project
+
+    prj.create_file 'main.cpp', <<~SRC
+      #include <iostream>
+      #include <adder/adder.hpp>
+      int main() {
+          std::cout << adder::add(1, 2) << '\\n';
+          return 0;
+      }
+    SRC
+
+    prj.create_file 'CMakeLists.txt', <<~SRC
+      cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+      project(using-adder)
+      set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
+      include("%{cpm_path}")
+      CPMAddPackage("gh:cpm-cmake/testpack-adder@1.0.0")
+      add_executable(using-adder main.cpp)
+      target_link_libraries(using-adder adder)
+    SRC
+
+    assert_success prj.configure
+
+    cache = prj.read_cache
+    assert_equal 1, cache.packages.size
+    assert_equal '1.0.0', cache.packages['testpack-adder'].ver
+
+    assert_success prj.build
+  end
+end

test/style/CMakeLists.txt

@@ -6,7 +6,9 @@ include(${CMAKE_CURRENT_LIST_DIR}/../../cmake/CPM.cmake)
 
 CPMAddPackage(
   NAME Format.cmake
-  VERSION 1.6
+  VERSION 1.7.3
   GITHUB_REPOSITORY TheLartians/Format.cmake
-  OPTIONS "FORMAT_CHECK_CMAKE ON"
+  # We exclude cmake files from integration tests as they contain invalid lines of code which are
+  # used by the integration test scripts
+  OPTIONS "CMAKE_FORMAT_EXCLUDE integration/templates"
 )

test/unit/cache.cmake

@@ -26,6 +26,17 @@ function(reset_test)
   update_cmake_lists()
 endfunction()
 
+function(assert_cache_directory_count directory count)
+  set(version_count 0)
+  file(GLOB potential_versions ${directory})
+  foreach(entry ${potential_versions})
+    if(IS_DIRECTORY ${entry})
+      math(EXPR version_count "${version_count} + 1")
+    endif()
+  endforeach()
+  assert_equal("${version_count}" "${count}")
+endfunction()
+
 set(FIBONACCI_VERSION 1.0)
 
 # Read CPM_SOURCE_CACHE from arguments
@@ -33,20 +44,14 @@ set(FIBONACCI_VERSION 1.0)
 reset_test()
 
 execute_process(
-  COMMAND ${CMAKE_COMMAND} "-H${CMAKE_CURRENT_LIST_DIR}/remote_dependency" "-B${TEST_BUILD_DIR}"
+  COMMAND ${CMAKE_COMMAND} "-S${CMAKE_CURRENT_LIST_DIR}/remote_dependency" "-B${TEST_BUILD_DIR}"
           "-DCPM_SOURCE_CACHE=${CPM_SOURCE_CACHE_DIR}" RESULT_VARIABLE ret
 )
 
 assert_equal(${ret} "0")
 assert_exists("${CPM_SOURCE_CACHE_DIR}/fibonacci")
 
-file(GLOB FIBONACCI_VERSIONs "${CPM_SOURCE_CACHE_DIR}/fibonacci/*")
+assert_cache_directory_count("${CPM_SOURCE_CACHE_DIR}/fibonacci/*" 1)
-list(LENGTH FIBONACCI_VERSIONs FIBONACCI_VERSION_count)
-assert_equal(${FIBONACCI_VERSION_count} "1")
-
-file(GLOB fibonacci_versions "${CPM_SOURCE_CACHE_DIR}/fibonacci/*")
-list(LENGTH fibonacci_versions fibonacci_version_count)
-assert_equal(${fibonacci_version_count} "1")
 
 # Update dependency and keep CPM_SOURCE_CACHE
 
@@ -54,12 +59,9 @@ set(FIBONACCI_VERSION 2.0)
 update_cmake_lists()
 
 execute_process(COMMAND ${CMAKE_COMMAND} ${TEST_BUILD_DIR} RESULT_VARIABLE ret)
-
 assert_equal(${ret} "0")
 
-file(GLOB FIBONACCI_VERSIONs "${CPM_SOURCE_CACHE_DIR}/fibonacci/*")
+assert_cache_directory_count("${CPM_SOURCE_CACHE_DIR}/fibonacci/*" 2)
-list(LENGTH FIBONACCI_VERSIONs FIBONACCI_VERSION_count)
-assert_equal(${FIBONACCI_VERSION_count} "2")
 
 # Clear cache and update
 
@@ -76,7 +78,7 @@ reset_test()
 
 execute_process(
   COMMAND ${CMAKE_COMMAND} -E env "CPM_SOURCE_CACHE=${CPM_SOURCE_CACHE_DIR}" ${CMAKE_COMMAND}
-          "-H${CMAKE_CURRENT_LIST_DIR}/remote_dependency" "-B${TEST_BUILD_DIR}" RESULT_VARIABLE ret
+          "-S${CMAKE_CURRENT_LIST_DIR}/remote_dependency" "-B${TEST_BUILD_DIR}" RESULT_VARIABLE ret
 )
 
 assert_equal(${ret} "0")
@@ -86,7 +88,7 @@ assert_exists("${CPM_SOURCE_CACHE_DIR}/fibonacci")
 
 execute_process(
   COMMAND ${CMAKE_COMMAND} -E env "CPM_SOURCE_CACHE=${CPM_SOURCE_CACHE_DIR}" ${CMAKE_COMMAND}
-          "-H${CMAKE_CURRENT_LIST_DIR}/remote_dependency" "-B${TEST_BUILD_DIR}-2"
+          "-S${CMAKE_CURRENT_LIST_DIR}/remote_dependency" "-B${TEST_BUILD_DIR}-2"
   RESULT_VARIABLE ret
 )
 
@@ -99,7 +101,7 @@ reset_test()
 execute_process(
   COMMAND
     ${CMAKE_COMMAND} -E env "CPM_SOURCE_CACHE=${CMAKE_CURRENT_BINARY_DIR}/junk" ${CMAKE_COMMAND}
-    "-H${CMAKE_CURRENT_LIST_DIR}/remote_dependency" "-B${TEST_BUILD_DIR}"
+    "-S${CMAKE_CURRENT_LIST_DIR}/remote_dependency" "-B${TEST_BUILD_DIR}"
     "-DCPM_SOURCE_CACHE=${CPM_SOURCE_CACHE_DIR}"
   RESULT_VARIABLE ret
 )
@@ -116,7 +118,7 @@ reset_test()
 
 execute_process(
   COMMAND ${CMAKE_COMMAND} -E env "CPM_SOURCE_CACHE=${CPM_SOURCE_CACHE_DIR}" ${CMAKE_COMMAND}
-          "-H${CMAKE_CURRENT_LIST_DIR}/remote_dependency" "-B${TEST_BUILD_DIR}" RESULT_VARIABLE ret
+          "-S${CMAKE_CURRENT_LIST_DIR}/remote_dependency" "-B${TEST_BUILD_DIR}" RESULT_VARIABLE ret
 )
 
 assert_equal(${ret} "0")
@@ -130,8 +132,24 @@ update_cmake_lists()
 
 execute_process(
   COMMAND ${CMAKE_COMMAND} -E env "CPM_SOURCE_CACHE=${CPM_SOURCE_CACHE_DIR}" ${CMAKE_COMMAND}
-          "-H${CMAKE_CURRENT_LIST_DIR}/remote_dependency" "-B${TEST_BUILD_DIR}" RESULT_VARIABLE ret
+          "-S${CMAKE_CURRENT_LIST_DIR}/remote_dependency" "-B${TEST_BUILD_DIR}" RESULT_VARIABLE ret
 )
 
 assert_equal(${ret} "0")
 assert_not_exists("${CPM_SOURCE_CACHE_DIR}/fibonacci")
+
+# Use custom cache directory
+
+set(FIBONACCI_PACKAGE_ARGS
+    "CUSTOM_CACHE_KEY my_custom_unique_dir GIT_TAG e9ebf168ca0fffaa4ef8c6fefc6346aaa22f6ed5"
+)
+set(FIBONACCI_VERSION 1.1)
+update_cmake_lists()
+
+execute_process(
+  COMMAND ${CMAKE_COMMAND} -E env "CPM_SOURCE_CACHE=${CPM_SOURCE_CACHE_DIR}" ${CMAKE_COMMAND}
+          "-S${CMAKE_CURRENT_LIST_DIR}/remote_dependency" "-B${TEST_BUILD_DIR}" RESULT_VARIABLE ret
+)
+
+assert_equal(${ret} "0")
+assert_exists("${CPM_SOURCE_CACHE_DIR}/fibonacci/my_custom_unique_dir")

test/unit/dependency_properties.cmake

@@ -6,6 +6,7 @@ include(${CPM_PATH}/testing.cmake)
 set(CPM_DRY_RUN ON)
 
 CPMAddPackage(NAME A GIT_TAG 1.2.3)
+assert_equal("${CPM_LAST_PACKAGE_NAME}" "A")
 
 CPMAddPackage(NAME A VERSION 1.2.3)
 
@@ -17,6 +18,8 @@ CPMAddPackage(NAME B VERSION 2.4.1)
 CPMAddPackage(NAME B GIT_TAG v2.3.1)
 
 CPMGetPackageVersion(B VERSION)
+assert_equal("${CPM_LAST_PACKAGE_NAME}" "B")
+
 assert_equal(${VERSION} "2.4.1")
 
 CPMAddPackage(
@@ -24,6 +27,10 @@ CPMAddPackage(
   GIT_TAG v3.1.2-a
   VERSION 3.1.2
 )
+assert_equal("${CPM_LAST_PACKAGE_NAME}" "C")
 
 CPMGetPackageVersion(C VERSION)
 assert_equal(${VERSION} "3.1.2")
+
+CPMAddPackage("gh:dry-run/D")
+assert_equal("${CPM_LAST_PACKAGE_NAME}" "D")

test/unit/exclude_from_all.cmake

@@ -11,7 +11,7 @@ function(init_project EXCLUDE_FROM_ALL)
   )
 
   execute_process(
-    COMMAND ${CMAKE_COMMAND} "-H${CMAKE_CURRENT_LIST_DIR}/broken_dependency" "-B${TEST_BUILD_DIR}"
+    COMMAND ${CMAKE_COMMAND} "-S${CMAKE_CURRENT_LIST_DIR}/broken_dependency" "-B${TEST_BUILD_DIR}"
     RESULT_VARIABLE ret
   )
 

test/unit/fetchcontent_dependency.cmake

@@ -31,7 +31,7 @@ endfunction()
 reset_test()
 
 execute_process(
-  COMMAND ${CMAKE_COMMAND} "-H${CMAKE_CURRENT_LIST_DIR}/fetchcontent_dependency"
+  COMMAND ${CMAKE_COMMAND} "-S${CMAKE_CURRENT_LIST_DIR}/fetchcontent_dependency"
           "-B${TEST_BUILD_DIR}" "-DCPM_SOURCE_CACHE=${CPM_SOURCE_CACHE_DIR}" RESULT_VARIABLE ret
 )
 

test/unit/get_shortest_hash.cmake

@@ -0,0 +1,93 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+include(${CPM_PATH}/CPM.cmake)
+include(${CPM_PATH}/testing.cmake)
+
+# Random suffix
+string(
+  RANDOM
+  LENGTH 6
+  ALPHABET "0123456789abcdef" tmpdir_suffix
+)
+
+# Seconds since epoch
+string(TIMESTAMP tmpdir_base "%s" UTC)
+
+set(tmp "${CMAKE_CURRENT_BINARY_DIR}/get_shortest_hash-${tmpdir_base}-${tmpdir_suffix}")
+
+if(IS_DIRECTORY ${tmp})
+  message(FATAL_ERROR "Test directory ${tmp} already exists")
+endif()
+
+file(MAKE_DIRECTORY "${tmp}")
+
+# 1. Sanity check: none of these directories should exist yet
+
+assert_not_exists(${tmp}/cccb.hash)
+assert_not_exists(${tmp}/cccb77ae.hash)
+assert_not_exists(${tmp}/cccb77ae9609.hash)
+assert_not_exists(${tmp}/cccb77ae9608.hash)
+assert_not_exists(${tmp}/cccb77be.hash)
+
+# 1. The directory is empty, so it should get a 4-character hash
+cpm_get_shortest_hash(${tmp} "cccb77ae9609d2768ed80dd42cec54f77b1f1455" hash)
+assert_equal(${hash} "cccb")
+assert_contents_equal(${tmp}/cccb.hash cccb77ae9609d2768ed80dd42cec54f77b1f1455)
+
+# 1. Calling the function with a new hash that differs subtly should result in more characters being
+#   used, enough to uniquely identify the hash
+
+cpm_get_shortest_hash(${tmp} "cccb77ae9609d2768ed80dd42cec54f77b1f1456" hash)
+assert_equal(${hash} "cccb77ae")
+assert_contents_equal(${tmp}/cccb77ae.hash cccb77ae9609d2768ed80dd42cec54f77b1f1456)
+
+cpm_get_shortest_hash(${tmp} "cccb77ae9609d2768ed80dd42cec54f77b1f1457" hash)
+assert_equal(${hash} "cccb77ae9609")
+assert_contents_equal(${tmp}/cccb77ae9609.hash cccb77ae9609d2768ed80dd42cec54f77b1f1457)
+
+cpm_get_shortest_hash(${tmp} "cccb77ae9608d2768ed80dd42cec54f77b1f1455" hash)
+assert_equal(${hash} "cccb77ae9608")
+assert_contents_equal(${tmp}/cccb77ae9608.hash cccb77ae9608d2768ed80dd42cec54f77b1f1455)
+
+cpm_get_shortest_hash(${tmp} "cccb77be9609d2768ed80dd42cec54f77b1f1456" hash)
+assert_equal(${hash} "cccb77be")
+assert_contents_equal(${tmp}/cccb77be.hash cccb77be9609d2768ed80dd42cec54f77b1f1456)
+
+# check that legacy hashs are recognized
+file(MAKE_DIRECTORY "${tmp}/cccb77be9609d2768ed80dd42cec54f77b1f1457")
+cpm_get_shortest_hash(${tmp} "cccb77be9609d2768ed80dd42cec54f77b1f1457" hash)
+assert_equal(${hash} "cccb77be9609d2768ed80dd42cec54f77b1f1457")
+
+# 1. The old file should still exist, and have the same content
+assert_contents_equal(${tmp}/cccb.hash cccb77ae9609d2768ed80dd42cec54f77b1f1455)
+assert_contents_equal(${tmp}/cccb77ae.hash cccb77ae9609d2768ed80dd42cec54f77b1f1456)
+assert_contents_equal(${tmp}/cccb77ae9609.hash cccb77ae9609d2768ed80dd42cec54f77b1f1457)
+assert_contents_equal(${tmp}/cccb77ae9608.hash cccb77ae9608d2768ed80dd42cec54f77b1f1455)
+assert_contents_equal(${tmp}/cccb77be.hash cccb77be9609d2768ed80dd42cec54f77b1f1456)
+
+# 1. Confirm idempotence: calling any of these function should produce the same hash as before (hash
+#   lookups work correctly once the .hash files are created)
+
+cpm_get_shortest_hash(${tmp} "cccb77ae9609d2768ed80dd42cec54f77b1f1455" hash)
+assert_equal(${hash} "cccb")
+assert_contents_equal(${tmp}/cccb.hash cccb77ae9609d2768ed80dd42cec54f77b1f1455)
+
+cpm_get_shortest_hash(${tmp} "cccb77ae9609d2768ed80dd42cec54f77b1f1456" hash)
+assert_equal(${hash} "cccb77ae")
+assert_contents_equal(${tmp}/cccb77ae.hash cccb77ae9609d2768ed80dd42cec54f77b1f1456)
+
+cpm_get_shortest_hash(${tmp} "cccb77ae9609d2768ed80dd42cec54f77b1f1457" hash)
+assert_equal(${hash} "cccb77ae9609")
+assert_contents_equal(${tmp}/cccb77ae9609.hash cccb77ae9609d2768ed80dd42cec54f77b1f1457)
+
+cpm_get_shortest_hash(${tmp} "cccb77ae9608d2768ed80dd42cec54f77b1f1455" hash)
+assert_equal(${hash} "cccb77ae9608")
+assert_contents_equal(${tmp}/cccb77ae9608.hash cccb77ae9608d2768ed80dd42cec54f77b1f1455)
+
+cpm_get_shortest_hash(${tmp} "cccb77be9609d2768ed80dd42cec54f77b1f1456" hash)
+assert_equal(${hash} "cccb77be")
+assert_contents_equal(${tmp}/cccb77be.hash cccb77be9609d2768ed80dd42cec54f77b1f1456)
+
+# 1. Cleanup - remove the temporary directory that we created
+
+file(REMOVE_RECURSE ${tmp})

test/unit/local_dependency/ModuleCMakeLists.txt.in

@@ -8,6 +8,10 @@ option(ENABLE_TEST_COVERAGE "Enable test coverage" OFF)
 
 # ---- Dependencies ----
 
+if (@TEST_FORCE_MODULE_MODE@)
+  unset(CMAKE_FIND_PACKAGE_REDIRECTS_DIR CACHE)
+endif()
+
 include(@CPM_PATH@/CPM.cmake)
 
 CPMAddPackage(
@@ -15,20 +19,23 @@ CPMAddPackage(
   SOURCE_DIR ${CMAKE_CURRENT_LIST_DIR}/dependency
 )
 
-# ---- check if generated modules override find_package ----
-
-if (@test_check_find_package@)
-  find_package(@TEST_DEPENDENCY_NAME@ REQUIRED)
-endif()
-
 # ---- Call dependency method to validate correct addition of directory ----
 
 dependency_function()
 
-# ---- Check parameters ----
+# ---- Check newly added ----
-
 include(@CPM_PATH@/testing.cmake)
-
 ASSERT_TRUTHY(@TEST_DEPENDENCY_NAME@_ADDED)
+
+# ---- Check if generated modules override find_package ----
+
+if (@TEST_FIND_PACKAGE@)
+  find_package(@TEST_DEPENDENCY_NAME@ @TEST_FIND_PACKAGE_CONFIG@ REQUIRED)
+  find_package(@TEST_CANT_FIND_PACKAGE_NAME@ @TEST_FIND_PACKAGE_CONFIG@ QUIET)
+  ASSERT_FALSY(@TEST_CANT_FIND_PACKAGE_NAME@_FOUND)
+endif()
+
+# ---- Check parameters ----
 ASSERT_DEFINED(@TEST_DEPENDENCY_NAME@_SOURCE_DIR)
 ASSERT_DEFINED(@TEST_DEPENDENCY_NAME@_BINARY_DIR)
+ASSERT_EQUAL("${CPM_LAST_PACKAGE_NAME}" "@TEST_DEPENDENCY_NAME@")

test/unit/local_dependency/OptionsCMakeLists.txt.in

@@ -13,7 +13,9 @@ include(@CPM_PATH@/CPM.cmake)
 CPMAddPackage(
   NAME Dependency
   SOURCE_DIR ${CMAKE_CURRENT_LIST_DIR}/dependency
-  OPTIONS "DEFINE_ALTERNATIVE_FUNCTION YES"
+  OPTIONS
+    "DEFINE_ALTERNATIVE_FUNCTION YES"
+    "LIST_ARGUMENT a\\\\;b\\\\;c"
   EXCLUDE_FROM_ALL YES
 )
 

test/unit/local_dependency/OverrideCMakeLists.txt.in

@@ -25,3 +25,5 @@ include(@CPM_PATH@/testing.cmake)
 ASSERT_TRUTHY(Dependency_ADDED)
 ASSERT_DEFINED(Dependency_SOURCE_DIR)
 ASSERT_DEFINED(Dependency_BINARY_DIR)
+ASSERT_EQUAL("${CPM_LAST_PACKAGE_NAME}" "Dependency")
+

test/unit/local_dependency/dependency/CMakeLists.txt

@@ -8,6 +8,12 @@ if(NOT DEFINE_ALTERNATIVE_FUNCTION)
     message("called external method")
   endfunction()
 else()
+
+  # check if list was passed correctly
+  if(NOT "${LIST_ARGUMENT}" STREQUAL "a;b;c")
+    message(FATAL_ERROR "list argument not properly passed to dependency: '${LIST_ARGUMENT}'")
+  endif()
+
   function(alternative_dependency_function)
     message("called alternative external method")
   endfunction()

test/unit/modules.cmake

@@ -3,7 +3,8 @@ include(${CPM_PATH}/testing.cmake)
 
 set(TEST_BUILD_DIR ${CMAKE_CURRENT_BINARY_DIR}/modules)
 
-function(init_project_with_dependency TEST_DEPENDENCY_NAME)
+function(init_project_with_dependency TEST_DEPENDENCY_NAME TEST_CANT_FIND_PACKAGE_NAME)
+  set(TEST_FIND_PACKAGE ON)
   configure_package_config_file(
     "${CMAKE_CURRENT_LIST_DIR}/local_dependency/ModuleCMakeLists.txt.in"
     "${CMAKE_CURRENT_LIST_DIR}/local_dependency/CMakeLists.txt"
@@ -11,18 +12,24 @@ function(init_project_with_dependency TEST_DEPENDENCY_NAME)
   )
 
   execute_process(
-    COMMAND ${CMAKE_COMMAND} "-H${CMAKE_CURRENT_LIST_DIR}/local_dependency" "-B${TEST_BUILD_DIR}"
+    COMMAND ${CMAKE_COMMAND} "-S${CMAKE_CURRENT_LIST_DIR}/local_dependency" "-B${TEST_BUILD_DIR}"
     RESULT_VARIABLE ret
   )
 
   assert_equal(${ret} "0")
 endfunction()
 
-init_project_with_dependency(A)
+init_project_with_dependency(A B)
-assert_exists(${TEST_BUILD_DIR}/CPM_modules)
+init_project_with_dependency(B A)
-assert_exists(${TEST_BUILD_DIR}/CPM_modules/FindA.cmake)
-assert_not_exists(${TEST_BUILD_DIR}/CPM_modules/FindB.cmake)
 
-init_project_with_dependency(B)
+if(${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.24.0")
-assert_not_exists(${TEST_BUILD_DIR}/CPM_modules/FindA.cmake)
+  set(TEST_FIND_PACKAGE_CONFIG CONFIG)
-assert_exists(${TEST_BUILD_DIR}/CPM_modules/FindB.cmake)
+  init_project_with_dependency(A B)
+  init_project_with_dependency(B A)
+
+  # Test the fallback path for CMake <3.24 works
+  set(TEST_FIND_PACKAGE_CONFIG)
+  set(TEST_FORCE_MODULE_MODE ON)
+  init_project_with_dependency(A B)
+  init_project_with_dependency(B A)
+endif()

test/unit/options.cmake

@@ -12,7 +12,7 @@ configure_package_config_file(
 )
 
 execute_process(
-  COMMAND ${CMAKE_COMMAND} "-H${CMAKE_CURRENT_LIST_DIR}/local_dependency" "-B${TEST_BUILD_DIR}"
+  COMMAND ${CMAKE_COMMAND} "-S${CMAKE_CURRENT_LIST_DIR}/local_dependency" "-B${TEST_BUILD_DIR}"
   RESULT_VARIABLE ret
 )
 

test/unit/package-lock.cmake

@@ -24,7 +24,7 @@ function(configure_with_declare DECLARE_DEPENDENCY)
   )
 
   execute_process(
-    COMMAND ${CMAKE_COMMAND} -H${CMAKE_CURRENT_LIST_DIR}/local_dependency -B${TEST_BUILD_DIR}
+    COMMAND ${CMAKE_COMMAND} -S${CMAKE_CURRENT_LIST_DIR}/local_dependency -B${TEST_BUILD_DIR}
             -DCPM_INCLUDE_ALL_IN_PACKAGE_LOCK=1 RESULT_VARIABLE ret
   )
 

test/unit/package-override.cmake

@@ -12,7 +12,7 @@ configure_package_config_file(
 )
 
 execute_process(
-  COMMAND ${CMAKE_COMMAND} -H${CMAKE_CURRENT_LIST_DIR}/local_dependency -B${TEST_BUILD_DIR}
+  COMMAND ${CMAKE_COMMAND} -S${CMAKE_CURRENT_LIST_DIR}/local_dependency -B${TEST_BUILD_DIR}
           -DCPM_Dependency_SOURCE=${CMAKE_CURRENT_LIST_DIR}/local_dependency/dependency
   RESULT_VARIABLE ret
 )

test/unit/remote_dependency/CMakeLists.txt.in

@@ -30,3 +30,4 @@ include(@CPM_PATH@/testing.cmake)
 ASSERT_TRUTHY(fibonacci_ADDED)
 ASSERT_DEFINED(fibonacci_SOURCE_DIR)
 ASSERT_DEFINED(fibonacci_BINARY_DIR)
+ASSERT_EQUAL("${CPM_LAST_PACKAGE_NAME}" "fibonacci")

test/unit/source_dir.cmake

@@ -12,7 +12,7 @@ configure_package_config_file(
 )
 
 execute_process(
-  COMMAND ${CMAKE_COMMAND} "-H${CMAKE_CURRENT_LIST_DIR}/local_dependency" "-B${TEST_BUILD_DIR}"
+  COMMAND ${CMAKE_COMMAND} "-S${CMAKE_CURRENT_LIST_DIR}/local_dependency" "-B${TEST_BUILD_DIR}"
   RESULT_VARIABLE ret
 )
 

test/unit/subdir.cmake

@@ -10,7 +10,7 @@ configure_package_config_file(
 )
 
 execute_process(
-  COMMAND ${CMAKE_COMMAND} "-H${CMAKE_CURRENT_LIST_DIR}/local_dependency" "-B${TEST_BUILD_DIR}"
+  COMMAND ${CMAKE_COMMAND} "-S${CMAKE_CURRENT_LIST_DIR}/local_dependency" "-B${TEST_BUILD_DIR}"
   RESULT_VARIABLE ret
 )