Phillip, You're right. I was running the tests on my two Windows Vista environments, and now I discover the problem only exhibits itself under Windows. I expanded the packages to my Ubuntu 8.04 box, and after installing nose (as you pointed out), the tests also ran (minimally) without incident. I then copied the packages to a brand-new Windows Vista install. I installed Python 2.5.2, setuptools-0.6c8, and nose 0.10.3. I then installed myns.projA using develop, and attempted to run "setup.py test" on myns.projB, and the error did exhibit itself. Additionally, I tested the sample on Windows XP (Python 2.5.2) and it also exhibits the error. Thanks to your help, I've further narrowed down the problem. I have filed a ticket with the nose tracker: http://code.google.com/p/python-nose/issues/detail?id=197 Any further suggestions are always appreciated. Regards, Jason -----Original Message----- From: Phillip J. Eby [mailto:pje@telecommunity.com] Sent: Sunday, 29 June, 2008 21:21 To: Jason R. Coombs; distutils-sig@python.org Subject: Re: [Distutils] ImportError running 'test' on namespace package - other package in namespace not found I can't reproduce this using the archive you uploaded. After running develop on projA, I ran test on projB and got an error message about nose not being available, so I added tests_require="nose" to projB, and then I got a run that said zero tests ran.