Comment 2 for bug 452774

Okay I've investigated more and this really has nothing to do with the difference between Python 2.6.4rc1 upstream and Python 2.6.4rc1 in Ubuntu. It is just an accident that when I test with the upstream version then my build script doesn't find Twisted (because it doesn't have /usr/lib/python2.6/dist-packages in its sys.path) and therefore it automatically installs a copy of Twisted for me, and then the test passes because that copy of Twisted is installed in a place where it can be found during the test. If I use the Ubuntu version of Python then it does not install a copy of Twisted (since Twisted is already installed and /usr/lib/python2.6/dist-packages is in the sys.path), but it is installed in such a way that its 'twistd' script can't be run by the "pkg_resources.run_script()" command so the test fails.