John Hunter wrote: > Andrew, the failure is on the font cache again -- is this the race > condition you've mentioned in the past? > > matplotlib.tests.test_mathtext.test_mathtext_stixsans ... ok > Failure: IOError ([Errno 2] No such file or directory: > '/home/mpl-chslave/.matplotlib/fontList.cache') ... ERROR > > "/home/mpl-chslave/slave-py24/build_test_py24/build/PYmpl/lib/python2.4/site-packages/matplotlib/font_manager.py", > line 942, in pickle_dump > fh = open(filename, 'w') > IOError: [Errno 2] No such file or directory: > '/home/mpl-chslave/.matplotlib/fontList.cache' John, yes, this is the multiprocess race condition. I don't think the issue is buildbot specific, but I can see that the use case may be rare in which one process deletes the MPL directory after another had already determined it is present. Nevertheless, I think it's something that could happen in other circumstances, and I'm not sure the fontlist cache file itself is multiprocess safe (I'm not saying it isn't -- I haven't looked). It does appear that a locking based solution is possible in a cross-platform way, as sqlite says they do it in "Can multiple applications or multiple instances of the same application access a single database file at the same time?" at http://www.sqlite.org/faq.html . I could put the builds in different user accounts so that the buildbot wouldn't unintentionally continue to be hit with this bug. We could also make a test case that starts multiple processes simultaneously using subprocess to exercise the bug and mark it as known failing -- that way we at least don't forget that it's an issue. All that being said -- I don't mind the occasional buildbot failure message -- it tells me that the buildbot is running and testing stuff. One can always quickly re-fire the failed test manually from the buildbot webpage to determine if this was the problem. -Andrew