Bug#1112076: gcr4: test-ssh-agent-service (gcr:gcr-ssh-agent / service) intermittently hangs

[Simon McVittie]

On Tue, 26 Aug 2025 at 00:19:26 +0100, Luca Boccassi wrote:
>The gcr4 autopkgtests seem to get stuck for hours until timing out in
>the installed-tests test.

This was really at least two bugs:

1. test-ssh-agent-service (aka gcr:gcr-ssh-agent / service when run as a
    build-time test) intermittently gets stuck and does not terminate
    until killed by a timeout. I sometimes see this when building gcr4
    locally, especially if built in parallel with other packages (a race
    condition triggered by system load?), but it's intermittent.

2. debian/tests/installed-tests didn't put any timeout on individual
    test-cases. Fix pending.

As a stopgap answer to the autopkgtests often failing (#1112076) and the 
build intermittently failing (no bug report), I'm going to patch the 
failing test-case to not run by default. As with similar workarounds in 
GLib, it can be re-enabled by exporting DEB_ALLOW_FLAKY_TESTS=1.

(1.) is still a valid bug, so I've cloned #1112659 to represent it. I 
don't have the domain knowledge or the spoons to dig further into it 
right now - help welcome. A first step would be to reproduce it, get a 
backtrace and report it upstream.

It seems that #1112659 is more reproducible on riscv64 than on other 
architectures. If it's a race condition (as I suspect), then it might be 
correlated with having a slower CPU or high system load, so that would 
be a good place for someone to start investigating.

It looks as though test-ssh-agent-process might also be flaky. I'll open 
a separate bug for that.

     smcv