A buildbot produced the following traceback, but the test passed when re-run.  

http://buildbot.python.org/all/builders/x86%20Gentoo%203.3/builds/630/steps/test/logs/stdio

test_loader_deprecated (test.test_pkgutil.ImportlibMigrationTests) ... ok

======================================================================
ERROR: test_iter_importers (test.test_pkgutil.ExtendPathTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "<frozen importlib._bootstrap>", line 1521, in _find_and_load_unlocked
AttributeError: 'module' object has no attribute '__path__'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/var/lib/buildslave/3.3.murray-gentoo/build/Lib/test/test_pkgutil.py", line 206, in test_iter_importers
    importlib.import_module(fullname)
  File "/var/lib/buildslave/3.3.murray-gentoo/build/Lib/importlib/__init__.py", line 90, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1586, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1567, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1524, in _find_and_load_unlocked
ImportError: No module named 'spam.eggs'; spam is not a package

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/var/lib/buildslave/3.3.murray-gentoo/build/Lib/test/test_pkgutil.py", line 226, in test_iter_importers
    del sys.modules['spam.eggs']
KeyError: 'spam.eggs'