psycopg exceptions cannot be pickled

import psycopg2
conn = psycopg2.connect("dbname='somedb'")
cur = conn.cursor() 
try:
    cur.execute("SELECT * FROM barf")
except Exception, e:
    print e
    pass

import cPickle
a = cPickle.dumps(e)
l = cPickle.loads(a)

which gives:

relation "barf" does not exist
LINE 1: SELECT * FROM barf
                      ^
Traceback (most recent call last):
  File "<stdin>", line 11, in <module>
  File "/usr/lib/python2.6/copy_reg.py", line 70, in _reduce_ex
    raise TypeError, "can't pickle %s objects" % base.__name__
TypeError: can't pickle cursor objects

Exception pickling becomes an issue for example when one is using the multiprocessing module. See http://stackoverflow.com/questions/8785899/hang-in-python-script-us... , http://bugs.python.org/issue13751 , http://bugs.python.org/issue1692335 and http://www.sqlalchemy.org/trac/ticket/2371

See also http://stackoverflow.com/questions/2246384/multiprocessing-pool-han...

If you want I can produce a slightly more complicated example that uses multiprocessing, but I hope the given example is convincing. Thanks.