In Python 2.3.3, doctest chokes on classes which
contain an attribute of type super: 

Traceback (most recent call last):
  File "/ttt/private/tanzer/temp/confuse_doctest.py",
line 14, in ?
    import doctest, confuse_doctest
  File
"/Node/tttprime/ttt/private/tanzer/temp/confuse_doctest.py",
line 15, in ?
    doctest.testmod(confuse_doctest)
  File "/usr/lib/python2.3/doctest.py", line 1148, in
testmod
    f, t = tester.rundict(m.__dict__, name, m)
  File "/usr/lib/python2.3/doctest.py", line 908, in
rundict
    f2, t2 = self.__runone(value, name + "." + thisname)
  File "/usr/lib/python2.3/doctest.py", line 1069, in
__runone
    return self.rundoc(target, name)
  File "/usr/lib/python2.3/doctest.py", line 828, in rundoc
    f2, t2 = self.run__test__(d, name)
  File "/usr/lib/python2.3/doctest.py", line 937, in
run__test__
    raise TypeError("Tester.run__test__: values in "
TypeError: Tester.run__test__: values in dict must be
strings, functions, methods, or classes; <super: <class
'A'>, NULL>

A simple example triggering the bug is attached.

Python 2.3.3 (#2, Jan 13 2004, 00:47:05) 
[GCC 3.3.3 20040110 (prerelease) (Debian)] on linux2