New submission from Chris Jerdonek: I have observed that when running unit tests using unittest's test discovery, unittest can simultaneously (1) modify sys.path unnecessarily (by adding a path that is already in sys.path with a different case), and (2) modify sys.path by adding a path of the "wrong" case.
This occurs for me on Mac OS X with the default case-insensitive file system. If the path-- '/Users/chris/Dev/python/my_package' is already in sys.path, running unittest's test discovery will prepend sys.path with the following: '/Users/chris/dev/python/my_package' Aside from causing unnecessary modifications of sys.path, this also causes an issue in coverage, for example: https://bitbucket.org/ned/coveragepy/issue/348 The relevant code is here in unittest/loader.py (with `top_level_dir` starting out as os.curdir): top_level_dir = os.path.abspath(top_level_dir) if not top_level_dir in sys.path: # all test modules must be importable from the top level directory # should we *unconditionally* put the start directory in first # in sys.path to minimise likelihood of conflicts between installed # modules and development versions? sys.path.insert(0, top_level_dir) self._top_level_dir = top_level_dir (from https://hg.python.org/cpython/file/75ede5bec8db/Lib/unittest/loader.py#l259 ) The issue occurs when os.path.abspath(top_level_dir) is already in sys.path but with a different case. (Note that if os.path.abspath() returned a path with the "right" case, then the unittest code would be okay.) See also these two threads regarding obtaining the correct case for a path: 1. https://mail.python.org/pipermail/python-dev/2010-September/103823.html 2. https://mail.python.org/pipermail/python-ideas/2010-September/008153.html ---------- components: Library (Lib) messages: 232993 nosy: chris.jerdonek priority: normal severity: normal status: open title: unittest can unnecessarily modify sys.path (and with the wrong case) type: behavior versions: Python 3.4, Python 3.5 _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue23097> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com