kill(pid, 0) succeeds for a zombie. A caller that captures the wrapper's
output and calls communicate() after TERM leaves the wrapper unreaped while
the finalizer holds its pipes, so the owner check passed until the deadline
and the job was still closed (codex, round 2; reproduced with the real
registry). _alive now asks `ps -o stat=` (POSIX, no /proc) once kill(0)
succeeds and treats state Z as gone, as tests/conftest.py::_pid_alive does;
no ps answer keeps kill(0)'s verdict. The owner is looked at every 0.5 s.
Tests: TERM + communicate() with no wait() for both graces (stand-ins) and
for the timeout grace with the real registry, old vs new; a zombie is not
alive. All four fail on c5cebe6.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
GodopuandClaude Opus 5.5
518bedac5d