One problem I have with run_tests.py is that using the pychecker version
barfs on my. E.g. with hg5009:3766e0ca8e7a :

 python run_tests.py -c 
Running unit tests at level 1
Running unit tests from /home/bernhard/hacking/roundup/roundup-811/.
warning: couldn't find real module for class <class 'ssl.SSLError'> (module name: ssl)
warning: couldn't find real module for class <type 'ssl.SSLContext'> (module name: ssl)
warning: couldn't find real module for class <class 'ssl.SSLError'> (module name: ssl)
Traceback (most recent call last):
  File "run_tests.py", line 885, in <module>
    process_args()
  File "run_tests.py", line 875, in process_args
    bad = main(module_filter, test_filter, libdir)
  File "run_tests.py", line 637, in main
    import logging.config
  File "/usr/lib/python2.7/site-packages/pychecker/checker.py", line 391, in __import__
    pymodule = _orig__import__(name, globals, locals, fromlist)
  File "/usr/lib64/python2.7/logging/config.py", line 27, in <module>
    import sys, logging, logging.handlers, socket, struct, os, traceback, re
  File "/usr/lib/python2.7/site-packages/pychecker/checker.py", line 391, in __import__
    pymodule = _orig__import__(name, globals, locals, fromlist)
  File "/usr/lib64/python2.7/logging/handlers.py", line 26, in <module>
    import errno, logging, socket, os, cPickle, struct, time, re
  File "/usr/lib/python2.7/site-packages/pychecker/checker.py", line 391, in __import__
    pymodule = _orig__import__(name, globals, locals, fromlist)
TypeError: __import__() takes at most 4 arguments (5 given)