OK, at least part of my confusion is the whole cygwin/not-cygwin thing. I'm using distutils to install a package (PyGUI) like this: PyGUI-1.7.2 $ c:/Python2.5/python setup.py install --home=c:/GUI-test-install Initially I was giving --home=/cygdrive/c/GUI-test-install install (in the depths of some Makefile) and getting the 'cannot be absolute' message. Fixing that path, though (as above), the problem is that it DOES install, but actually into a relative path, PyGUI-1.7.2/GUI-test-install Isn't the whole point of --home to ALLOW an absolute path? Note also that doing something analogous on linux (with an absolute path) works fine. OK, and I've figured it out. I need to give it a path c:\\GUI-test-install. Which is not shocking, but certainly it would be NICE if distutils could treat '/' and '\\' as synonyms -- the underlying windows API does back since DOS. Never mind. :-) Here's some output with the still somewhat incorrect path for --home: ... running install_lib creating c:GUI-test-install creating c:GUI-test-install\lib creating c:GUI-test-install\lib\python creating c:GUI-test-install\lib\python\GUI creating c:GUI-test-install\lib\python\GUI\Cocoa copying build\lib\GUI\Cocoa\Applications.py -> c:GUI-test-install\lib\python\GUI\Cocoa ...