The logging module errors out if the multiprocessing module is not finished loading when logging.log() is called.

This can happen, for example, if a custom import hook is defined that causes third-party code to execute when the multiprocessing module gets to an import statement.  (autoinstall is an example of a package that defines such an import hook: http://pypi.python.org/pypi/autoinstall/0.1a2 )

Here is a stack trace of the issue in action:

  File "/Users/chris_g4/dev/apple/WebKit-git/WebKitTools/Scripts/webkitpy/executive.py", line 118, in cpu_count
    import multiprocessing
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/multiprocessing/__init__.py", line 60, in <module>
    import os
  File "/Users/chris_g4/dev/apple/WebKit-git/WebKitTools/Scripts/webkitpy/thirdparty/autoinstall.py", line 279, in find_module
    _logger.debug("find_module(%s, path=%s)" % (fullname, path))
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/logging/__init__.py", line 1036, in debug
    self._log(DEBUG, msg, args, **kwargs)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/logging/__init__.py", line 1164, in _log
    record = self.makeRecord(self.name, level, fn, lno, msg, args, exc_info, func, extra)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/logging/__init__.py", line 1139, in makeRecord
    rv = LogRecord(name, level, fn, lno, msg, args, exc_info, func)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/logging/__init__.py", line 279, in __init__
    self.processName = sys.modules['multiprocessing'].current_process().name
AttributeError: 'module' object has no attribute 'current_process'


Here is a possible fix (in logging/__init__.py):

         if not logMultiprocessing:
             self.processName = None
         # "current_process" might not be defined if multiprocessing is
         # not finished loading yet.  This can happen, for example, if
         # a custom import hook is defined that causes third-party code
         # to execute when the multiprocessing module calls import.
-        elif 'multiprocessing' not in sys.modules:
+        elif 'multiprocessing' not in sys.modules or \
+             'current_process' not in dir(sys.modules['multiprocessing']):
             self.processName = 'MainProcess'
         else:
             self.processName = sys.modules['multiprocessing'].current_process().name
         if logProcesses and hasattr(os, 'getpid'):
             self.process = os.getpid()