CI flake: unity-testsuite segfault

[clockwork-labs-bot]

Detected by CI Gremlin after a failed GitHub Actions attempt succeeded on rerun.

Tests:

• unity-testsuite

Error:
[Licensing::Module] Error: Access token is unavailable; failed to update
[Licensing::Client] Successfully updated license

Failed job runs:

• https://github.com/clockworklabs/SpacetimeDB/actions/runs/30624180848/job/91136348011 (unity-testsuite, attempt 1 -> 2)

Timeout detection:

• none

Context:

• none

[clockwork-labs-bot]

Diagnosis for the exact linked job/attempt: run 30624180848, job 91136348011, unity-testsuite, attempt 1.

GitHub's job API reports the linked job as run_attempt: 1, matching the ticket's failed attempt 1 -> 2 rerun. The workflow was public CI for PR #5636, head SHA 3e533a0f80a8602b2f5f5981ae819c7b85d8a39b; checkout used merge ref SHA bb3cb43cc15f87787b4bf853d271dba8d4ccaf2f.

The setup path got through checkout, .NET restore/package override, Rust/cache, local CLI install, Unity binding generation, meta check, SpacetimeDB startup, and publishing the unity-tests module. The failure happened in Run Unity tests during playmode.

Unity 2022.3.32f1 initially activated normally and logged Pro License: YES. After playmode started, the editor crashed about a minute later:

Testing in playmode
Segmentation fault (core dumped)
[Licensing::Module] Error: Access token is unavailable; failed to update
[Licensing::Client] Successfully updated license
Pro License: YES
Caught fatal signal - signo:11 code:1 errno:0 addr:(nil)
Unexpected exit code 139
cat: /github/workspace/artifacts/playmode-results.xml: No such file or directory
##[error]The process '/usr/bin/docker' failed with exit code 139

The visible root cause for this exact attempt is a Unity editor/container crash while entering or running playmode, not a SpacetimeDB assertion failure. The access-token line appears in the crash/cleanup output, but entitlement was active (Pro License: YES) and cleanup later successfully returned the entitlement/ULF license, so I would not classify this as the older inactive-headless-license failure.

Suggested updated title: CI flake: unity-testsuite Unity playmode SIGSEGV exit 139

Duplicate check in the Test Flakes project:

• Top duplicate candidate: none. I found similar Unity licensing tickets, but none close enough to mark as a duplicate of this playmode SIGSEGV / exit 139 failure.
• Related but not exact: CI flake: unity-testsuite - access token is unavailable #5302 tracks Unity access-token/update-license flakes; CI flake: unity-testsuite Unity headless license not active #5581 tracks License is not active (com.unity.editor.headless) / No valid Unity Editor license found; CI flake: unity-testsuite #5585 and CI flake: unity-testsuite Unity headless license not active #5626 are closed repeats of that inactive-headless-license signature.
• I also searched broader terms for the exact crash mechanism, including Unexpected exit code 139, Caught fatal signal signo:11, Segmentation fault (core dumped), burst_signal_handler, and mono_get_runtime_build_info, and did not find an older matching Test Flakes issue.

Leaving this open because the top duplicate is not #3285, #3290, or #3099, and there is no close duplicate candidate.