gonzo:[~/src/toolchain][master]$ ./pants clean-all

10:39:57 00:00 [main]
               See a report at: <http://localhost:51327/run/pants_run_2018_08_02_10_40_03_334_73d533d6a4774167826b820fe7a6b197>
10:40:03 00:06   [setup]
10:40:03 00:06     [parse]
               Executing tasks in goals: clean-all
10:40:03 00:06   [clean-all]
10:40:03 00:06     [ng-killall]
10:40:03 00:06     [kill-pantsd]
10:40:08 00:11     [clean-all]INFO] For async removal, run `./pants clean-all --async`

10:40:11 00:14   [complete]
               SUCCESS
objc[43533]: +[__NSPlaceholderDate initialize] may have been in progress in another thread when fork() was called.
objc[43533]: +[__NSPlaceholderDate initialize] may have been in progress in another thread when fork() was called. We cannot safely call it or ignore it in the fork() child process. Crashing instead. Set a breakpoint on objc_initializeAfterForkError to debug.
CRITICAL] 
CRITICAL] lost active connection to pantsd!
Exception caught: (<class 'pants.bin.remote_pants_runner.Terminated'>)
  File "/Users/benjyw/.cache/pants/setup/bootstrap-Darwin-x86_64/1.8.0/bin/pants", line 11, in <module>
    sys.exit(main())
  File "/Users/benjyw/.cache/pants/setup/bootstrap-Darwin-x86_64/1.8.0/lib/python2.7/site-packages/pants/bin/pants_loader.py", line 69, in main
    PantsLoader.run()
  File "/Users/benjyw/.cache/pants/setup/bootstrap-Darwin-x86_64/1.8.0/lib/python2.7/site-packages/pants/bin/pants_loader.py", line 65, in run
    cls.load_and_execute(entrypoint)
  File "/Users/benjyw/.cache/pants/setup/bootstrap-Darwin-x86_64/1.8.0/lib/python2.7/site-packages/pants/bin/pants_loader.py", line 58, in load_and_execute
    entrypoint_main()
  File "/Users/benjyw/.cache/pants/setup/bootstrap-Darwin-x86_64/1.8.0/lib/python2.7/site-packages/pants/bin/pants_exe.py", line 39, in main
    PantsRunner(exiter, start_time=start_time).run()
  File "/Users/benjyw/.cache/pants/setup/bootstrap-Darwin-x86_64/1.8.0/lib/python2.7/site-packages/pants/bin/pants_runner.py", line 39, in run
    return RemotePantsRunner(self._exiter, self._args, self._env, bootstrap_options).run()
  File "/Users/benjyw/.cache/pants/setup/bootstrap-Darwin-x86_64/1.8.0/lib/python2.7/site-packages/pants/bin/remote_pants_runner.py", line 162, in run
    self._run_pants_with_retry(port)
  File "/Users/benjyw/.cache/pants/setup/bootstrap-Darwin-x86_64/1.8.0/lib/python2.7/site-packages/pants/java/nailgun_client.py", line 218, in execute
    return self._session.execute(cwd, main_class, *args, **environment)
  File "/Users/benjyw/.cache/pants/setup/bootstrap-Darwin-x86_64/1.8.0/lib/python2.7/site-packages/pants/java/nailgun_client.py", line 91, in execute
    return self._process_session()
  File "/Users/benjyw/.cache/pants/setup/bootstrap-Darwin-x86_64/1.8.0/lib/python2.7/site-packages/pants/java/nailgun_client.py", line 66, in _process_session
    for chunk_type, payload in self.iter_chunks(self._sock, return_bytes=True):
  File "/Users/benjyw/.cache/pants/setup/bootstrap-Darwin-x86_64/1.8.0/lib/python2.7/site-packages/pants/java/nailgun_protocol.py", line 206, in iter_chunks
    chunk_type, payload = cls.read_chunk(sock, return_bytes)
  File "/Users/benjyw/.cache/pants/setup/bootstrap-Darwin-x86_64/1.8.0/lib/python2.7/site-packages/pants/java/nailgun_protocol.py", line 182, in read_chunk
    raise cls.TruncatedHeaderError('Failed to read nailgun chunk header ({!r}).'.format(e))

Exception message: abruptly lost active connection to pantsd runner: NailgunError(u'Problem talking to nailgun server (address: 127.0.0.1:58932, remote_pid: -43532): TruncatedHeaderError(u"Failed to read nailgun chunk header (TruncatedRead(u\'Expected 5 bytes before socket shutdown, instead received 0\',)).",)',)