Getting warnings are always bad and means something is broken, we
shouldn't pass the test suite with them.
Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1349>
background_file = files(join_paths('data', 'background.png'))
perf_testenv = testenv
-perf_testenv.set('G_DEBUG', 'fatal-criticals')
+perf_testenv.set('G_DEBUG', 'fatal-warnings')
perf_testenv.set('G_MESSAGES_DEBUG', 'GNOME Shell')
perf_testenv.set('GNOME_SHELL_DATADIR', data_builddir)
perf_testenv.set('GNOME_SHELL_BUILDDIR', src_builddir)