Hello all I'm trying to run the NumPy tests from inside the source tree. This depends on set_package_path() finding the package files I built. According to the set_package_path documentation: set_package_path should be called from a test_file.py that satisfies the following tree structure: <somepath>/<somedir>/test_file.py Then the first existing path name from the following list <somepath>/build/lib.<platform>-<version> <somepath>/.. My source tree (and probably everyone else's) looks like this: numpy numpy\build numpy\build\lib.<platform>-<version> ... numpy\core\tests\test_foo.py This means that set_package_path isn't going to do the right thing when trying to run these tests. And indeed, I get an ImportError when I try. A better strategy would probably be to search up from dirname(abspath(testfile)) until you reach the current working directory, instead of the hardcoded dirname(dirname(abspath(testfile)) currently being used. Pearu, think we could fix this (assuming it's broken and that I didn't miss something obvious)? Regards, Albert