[Buildbot-devel] fun race condition in old web front end for buildbot

[Dan Kegel]

This is probably a "who cares", but:

Running buildmaster circa April 2014, cf4c10c2372db16290c2bd1ab86d4a14227d5f13.

I told buildmaster to reload its configuration, then clicked on force
build on a builder (with a web page
that was already open before the reconfig).  It aborted with

web.Server Traceback (most recent call last):
exceptions.UnboundLocalError: local variable 'msg' referenced before assignment
/home/buildbot/master-state/sandbox/local/lib/python2.7/site-packages/twisted/internet/defer.py:1070
in _inlineCallbacks
1069            else:
1070                result = g.send(result)
1071        except StopIteration:
/home/buildbot/master-state/sandbox/buildbot-git/master/buildbot/status/web/builder.py:78
in force
77        # send the user back to the builder page
78        defer.returnValue(msg)
79
exceptions.UnboundLocalError: local variable 'msg' referenced before assignment

and no build was queued.  Retrying it later worked fine.