Twice today, I had the CQ fail to land a CL because of this bot. Here's a log:

https://build.chromium.org/p/tryserver.chromium.mac/builders/ios-device-gn/builds/32888/steps/compile/logs/stdio

/usr/bin/python /b/build/goma/goma_ctl.py restart
/usr/bin/python: can't open file '/b/build/goma/goma_ctl.py': [Errno 2] No such file or directory

/usr/bin/python /b/build/goma/goma_ctl.py jsonstatus /tmp/tmphVzFyI.json
/usr/bin/python: can't open file '/b/build/goma/goma_ctl.py': [Errno 2] No such file or directory
error while sending ts mon json_file=/tmp/tmphVzFyI.json: No JSON object could be decoded

/usr/bin/python /b/build/goma/goma_ctl.py stop
/usr/bin/python: can't open file '/b/build/goma/goma_ctl.py': [Errno 2] No such file or directory
No compiler_proxy-subproc.INFO to upload
No compiler_proxy.INFO to upload

/usr/bin/python /opt/infra-python/run.py infra.tools.send_monitoring_event --event-mon-run-type prod --build-event-type BUILD --event-mon-timestamp-kind POINT --event-logrequest-path /b/build/slave/ios-device-gn/.recipe_runtime/tmpIZEHkK/build_data/log_request_proto --build-event-goma-error GOMA_ERROR_UNKNOWN
<Thread(Thread-1, started 123145306509312)> ProcessRead: proc.stdout finished.
<Thread(Thread-1, started 123145306509312)> ProcessRead: cleaning up.
<Thread(Thread-3, started daemon 123145310715904)> TimedFlush: Finished
Traceback (most recent call last):
  File "/b/build/scripts/slave/compile.py", line 553, in <module>
<Thread(Thread-1, started 123145306509312)> ProcessRead: finished.
error: failed to start goma; fallback has been disabled
    sys.exit(real_main())
  File "/b/build/scripts/slave/compile.py", line 549, in real_main
    return main_ninja(options, args)
  File "/b/build/scripts/slave/compile.py", line 353, in main_ninja
    goma_ready, goma_cloudtail = goma_setup(options, env)
  File "/b/build/scripts/slave/compile.py", line 213, in goma_setup
    raise Exception('failed to start goma')
Exception: failed to start goma