As of Meson 0.57,
meson test only rebuilds test dependencies. The GNOME master, 40, and 3.38 runtimes have all been updated to Meson 0.57. If your CI has recently started failing, this is probably why. Ondrej shows an example here of how to avoid test failures when dependencies are missing by adding explicit dependencies. This particular example avoids appdata-validate and desktop-file-validate failures when the appdata and desktop files are not generated, but the same pattern applies to all manner of test failures that you might be seeing due to this change. If your tests are broken, you’re missing a dependency somewhere.