CI: taking way too much time under Windows, running into timeouts
Under Debian, the project compiles, and all tests pass, within less than 1'40''. Whereas Windows jobs take 13' or more, and often fail because of timeout in some test. Tripling the timeout from 300'' to 900'' did not help (and should be reverted lest the timeout becomes pointless).
Part of the difference between Debian and Windows can be explained by compile times, since we have no ccache under Windows. But most of the time difference, and all of the timeout problem, clearly comes from the tests. Note that these are tests that launch the actual GUI. To get a feeling, run ctest
in an interactive session.
I suspect the problem has to do with the way we are running Windows on a virtual machine. This could easily be checked by building and testing under native Windows.