Bug#1017724: libaperture-0: flaky autopkgtest on multiple architectures: timeout_reached: code should not be reached

[Simon McVittie <smcv@debian.org>]

Source: libaperture-0
Version: 0.1.0+git20200908-3
Severity: serious
X-Debbugs-CC: debian-ci@lists.debian.org
User: debian-ci@lists.debian.org
Usertags: flaky

The autopkgtest for libaperture-0 seems to be intermittently failing
with a timeout, particularly on armel and armhf. Some examples:

- https://ci.debian.net/data/autopkgtest/testing/armel/liba/libaperture-0/24979047/log.gz
- https://ci.debian.net/data/autopkgtest/testing/armhf/liba/libaperture-0/23940701/log.gz
- https://ci.debian.net/data/autopkgtest/testing/amd64/liba/libaperture-0/23958726/log.gz

all of which look like this:

> ok 8 /viewfinder/no_camera
> # Aperture-DEBUG: New camera detected: Dummy Camera
> Bail out! ERROR:utils.c:48:timeout_reached: code should not be reached
> **
> ERROR:utils.c:48:timeout_reached: code should not be reached
> Aborted

When testing a proposed update to a package it depends on (such as
gdk-pixbuf or glibc), the test failure is assumed to be a regression in
the updated package, which can delay or prevent testing migration.

Please look into whether this test can be made reliable, or if it cannot,
mark the test with "Restrictions: flaky" so that it doesn't disrupt other
packages.

Upstream commit
https://gitlab.gnome.org/jwestman/libaperture/-/commit/b5bd52a63994becadd5be88814824c0679f85046
looks potentially relevant.

Thanks,
    smcv