Writing tests' output to a log file makes them difficult to debug when
the test might be running on an autobuilder or CI system where only
stdout/stderr are recorded. This is particularly troublesome if a
failure is only reproducible on a particular autobuilder.
Recent Automake versions have the convention that detailed output from
failing tests is written to stdout/stderr, not just to log files, when
the VERBOSE environment variable is set; borrow that convention as a
trigger for producing detailed test output.
This was originally cogl!14, but applies equally to mutter's fork of cogl.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1273
Signed-off-by: Simon McVittie <smcv@debian.org>
8ae641aa24