We can't rely on sip to generate these -- it outputs malformed
docstrings where the constructor docs are incorrectly placed
before the class docstrings
The typedef is only present in the .sip file, but without this
annotation SIP assumes it also exists in QGIS headers. This didn't
completely break the build, since we concatenate multiple SIP headers
into larger files, so the typedefs from one part "fixed" another. Run
sip-build without --concatenate to see the issue clearly.
This fix is currently sadly not fully effective due to a SIP bug:
https://github.com/Python-SIP/sip/issues/66
