Reading /proc/<pid>/stat for a process that is reaped during the read raises
ProcessLookupError (ESRCH), not FileNotFoundError. The previous race fix caught only
the latter, so the hanging-process-group test failed twice today under full-suite
load. It passed alone. The disappearance is exactly what the test asserts.
Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01EmM1j46qgKMh3zqD1QMwEo
`test_hanging_process_group_killed_inside_shared_allowance` failed about one
run in thirty under load with FileNotFoundError: it checked that
/proc/<pid>/stat existed, the killed process was reaped, and the read then
failed. A reaped process is the outcome the test wants, so it now reads and
treats a missing entry as gone. The engine-stage test had the same race.
150 of 150 runs pass under engine load.
Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01EmM1j46qgKMh3zqD1QMwEo
