Bug#995929: mutter: FTBFS on armel|armhf|arm64: build-time test core+mutter/unit / normal times out

[Simon McVittie <smcv@debian.org>]

Source: mutter
Version: 41.0-1
Severity: serious
Tags: ftbfs experimental
Justification: fails to build from source (but built successfully in the past)
X-Debbugs-Cc: debian-arm@lists.debian.org

The new version of mutter in experimental includes a build-time unit test
"core+mutter/unit / normal" which succeeds in about 20 seconds on for example
i386 and ppc64el, but fails with a timeout (after 6 minutes) on all three
ARM-based release architectures: armel, armhf, arm64.

I initially suspected this might be because we are forcing GLES2 rather than
"big GL" on armel and armhf, but arm64 fails in the same way and is not
forcing use of GLES2. Maybe one of our dependencies, like perhaps Mesa or
X11, has a special case for all three ARM-based release architectures?

Any ideas?

    smcv