cPickle is broken in Python <= 2.5.

It unsafely and incorrectly uses relative instead of absolute imports,
so e.g.:
      exceptions.KeyError
becomes:
      celery.exceptions.KeyError

Your best choice is to upgrade to Python 2.6,
as while the pure pickle version has worse performance,
it is the only safe option for older Python versions.

Please enter the commit message for your changes. Lines starting
with '#' will be ignored, and an empty message aborts the commit.

celery/serialization.py

@@ -1,13 +1,31 @@
-try:
-    import cPickle as pickle
-except ImportError:
-    import pickle
 import inspect
 import sys
 import types
 
 from copy import deepcopy
 
+import pickle as pypickle
+try:
+    import cPickle as cpickle
+except ImportError:
+    cpickle = None
+
+if sys.version_info() < (2, 6):
+    # cPickle is broken in Python <= 2.5.
+    # It unsafely and incorrectly uses relative instead of absolute imports,
+    # so e.g.:
+    #       exceptions.KeyError
+    # becomes:
+    #       celery.exceptions.KeyError
+    #
+    # Your best choice is to upgrade to Python 2.6,
+    # as while the pure pickle version has worse performance,
+    # it is the only safe option for older Python versions.
+    pickle = pypickle
+else:
+    pickle = cpickle or pypickle
+
+
 # BaseException was introduced in Python 2.5.
 try:
     _error_bases = (BaseException, )
@@ -55,7 +73,6 @@ def find_nearest_pickleable_exception(exc):
 
 
     for supercls in getmro_():
-        print("SUPERCLS: %s" % (supercls, ))
         if supercls in unwanted_base_classes:
             # only BaseException and object, from here on down,
             # we don't care about these.