On Wed, Apr 07, 2021 at 08:05:00PM -0400, Leo Famulari wrote: > .sip5-real: Unable to find file "QtXml/QtXmlmod.sip" I also noticed this passage in the QGIS ChangeLog: ------ Daniel Minor 2020-07-14 Fix FindPyQt5 cmake and python scripts As written, the FindPyQt5.cmake and FindPyQt5.py scripts will succeed even if PyQt5 is not installed. In FindPyQt5.cmake, we have PYQT5_FIND_REQUIRED rather than PyQt5_FIND_REQUIRED, so the package is always treated as though it is optional. In FindPyQt5.py, the script will succeed with a default location for the sip directory, even if the PyQt5 directory is not located. For some systems, if enough other dependencies are installed, the build can get about halfway complete without the main PyQt5 dependency, and then fail with a message like: sip: Unable to find file "QtXml/QtXmlmod.sip" I hit this building on Ubuntu, and there have been a few similar bug reports in the past. ------