[pantsd] Pantsd tries to write to a closed file when dying.

[blorente]

When running ./pants --enable-pantsd filter testprojects:: && ./pants kill-pantsd, the log doesn't render the exception properly, because out (possibly sys.stderr is closed when trying to write to it in exiter.py:

...
19:08:54 [INFO] pailgun request completed: `./pants --enable-pantsd filter testprojects::`
19:08:54 [INFO] enqueuing 24638 changes for subscription all_files
19:08:54 [INFO] confirmed watchman subscription: {'clock': 'c:1556046529:86379:1:3', 'subscribe': 'pantsd_pid', 'version': '4.9.1'}
19:08:54 [INFO] enqueuing 1 changes for subscription pantsd_pid
19:08:57 [WARN] Encountered error when trying to log this message: b'timestamp: 2019-04-23T20:08:57.454457\nSignal 15 (SIGTERM) was raised. Exiting with failure.\n  File "/Users/bescobar/workspace/pants/src/python/pants/bin/pants_loader.py", line 89, in <module>\n    main()\n  File "/Users/bescobar/workspace/pants/src/python/pants/bin/pants_loader.py", line 85, in main\n    PantsLoader.run()\n  File "/Users/bescobar/workspace/pants/src/python/pants/bin/pants_loader.py", line 81, in run\n    cls.load_and_execute(entrypoint)\n  File "/Users/bescobar/workspace/pants/src/python/pants/bin/pants_loader.py", line 74, in load_and_execute\n    entrypoint_main()\n  File "/Users/bescobar/workspace/pants/src/python/pants/pantsd/pants_daemon.py", line 475, in launch\n    PantsDaemon.Factory.create(OptionsBootstrapper.create()).run_sync()\n  File "/Users/bescobar/workspace/pants/src/python/pants/pantsd/pants_daemon.py", line 408, in run_sync\n    self._run_services(self._services)\n  File "/Users/bescobar/workspace/pants/src/python/pants/pantsd/pants_daemon.py", line 363, in _run_services\n    service_thread.join(self.JOIN_TIMEOUT_SECONDS)\n  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/threading.py", line 1036, in join\n    self._wait_for_tstate_lock(timeout=max(timeout, 0))\n  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/threading.py", line 1048, in _wait_for_tstate_lock\n    elif lock.acquire(block, timeout):\n  File "/Users/bescobar/workspace/pants/src/python/pants/base/exception_sink.py", line 74, in handle_sigterm\n    raise self.SignalHandledNonLocalExit(signum, \'SIGTERM\')\n  File "/Users/bescobar/workspace/pants/src/python/pants/base/exception_sink.py", line 67, in __init__\n    self.traceback_lines = traceback.format_stack()\n\n\n'

[stuhood]

And the theory is that this is not related to the implementation of kill-pantsd: only to receiving a signal.