fix subprocess on Windows (GH-391 backport) (GH-623)

diff --git a/Lib/subprocess.py b/Lib/subprocess.py
index 822ddb459e2615b99d93a5b440e7250679bde638..0db6571f291dae08d99b461f18233c7de7cd982f 100644 (file)
--- a/Lib/subprocess.py
+++ b/Lib/subprocess.py
@@ -986,7 +986,7 @@ class Popen(object):
                                          int(not close_fds),
                                          creationflags,
                                          env,
-                                         cwd,
+                                         os.fspath(cwd) if cwd is not None else None,
                                          startupinfo)
             finally:
                 # Child is launched. Close the parent's copy of those pipe