macos 15 x86_64 did not generate stacktrace on test crash.

See QTBUG-138477 for a test that got killed with SIGHUP but no stacktrace was printed.

agent:2025/07/07 23:37:17 build.go:412:         Start 171: tst_qquickmenu
agent:2025/07/07 23:39:51 build.go:463: Process finished with error: signal: hangup

workitem log:
https://testresults.qt.io/coin/log/qt/qtdeclarative/828b03c3e5837fc55a2313d3cfd3aecdbb05a87b/MacOSMacOS_15x86_64MacOSMacOS_15x86_64Clangqtci-macos-15-x86_64-103-6128f5Packaging_Sccache_TestOnly/88e5026163d29d9fe5666bb2e96d96980764ee27/forceRun/test_1751930089

Belongs to this HealthCheck from 7th of July:
https://testresults.qt.io/coin/integration/qt/qt5/tasks/nightly1751929381

If one downloads the full XML logs, it happens in <TestFunction name="subMenuMouse"> where the XML file gets truncated because of the crash.

EDIT: It seems the ctest parent process was killed first for unknown reason, because I can't find the summary files that CTest generates when it ends gracefully.
It might be that the message above "Process finished with error: signal: hangup" is printed by Coin about CTest, and CTest then dies without waiting for tst_qquickmenu to print a stacktrace.
If that's the case, then we can't expect stacktrace. The question then is: who and why killed ctest?