From a142f75cd7f4c0102428f9e6e7dddd00333baf0e Mon Sep 17 00:00:00 2001 From: Larry Hosken Date: Tue, 25 Mar 2014 08:45:25 -0700 Subject: [PATCH] doc: troubleshooting += Failed to read ng output after 5 seconds (sapling split of 42ea5a4ab21d9c1dfbd2c6e1bfb4756cc276872e) --- src/python/twitter/pants/docs/tshoot.rst | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/src/python/twitter/pants/docs/tshoot.rst b/src/python/twitter/pants/docs/tshoot.rst index 9a9fd61f829..77a9d3aa4ec 100644 --- a/src/python/twitter/pants/docs/tshoot.rst +++ b/src/python/twitter/pants/docs/tshoot.rst @@ -35,4 +35,24 @@ want to track down exactly what, you can reset your state:: $ build-support/python/clean.sh # clean cached files $ ./pants goal ng-killall --ng-killall-everywhere # stop background procs +***************** +Nailgun 5 seconds +***************** + +If Pants fails with a stack trace that ends with something like :: + + File "twitter/pants/tasks/nailgun_task.py", line 255, in _spawn_nailgun_server + File "twitter/pants/tasks/nailgun_task.py", line 226, in _await_nailgun_server + twitter.pants.java.nailgun_client.NailgunError: Failed to read ng output after 5 seconds + +Pants uses a program called nailgun to run some JVM jobs. Pants runs +nailgun as a server in the background and then sends requests to it. If +nailgun runs into problems, it might not respond. + +To debug this, look in ``./pants.d/ng/*/*``: these files should be named +``stdout`` and ``stderr``. + +One typical cause behind this symptom: if you removed your machine's Ivy cache, +Pants may try to use symbolic links to files that have gone away. +To recover from this, :ref:`washpants`.