--- Python-3.8.0/Lib/importlib/_bootstrap_external.py.orig 2019-12-21 14:31:23.806479400 +0100 +++ Python-3.8.0/Lib/importlib/_bootstrap_external.py 2019-12-21 14:34:37.093867400 +0100 @@ -1603,6 +1603,11 @@ continue else: raise ImportError('importlib requires posix or nt') + + if 'MSYSTEM' in os_module.environ: + path_separators = path_separators[::-1] + path_sep = path_separators[0] + setattr(self_module, '_os', os_module) setattr(self_module, 'path_sep', path_sep) setattr(self_module, 'path_separators', ''.join(path_separators))