fix None errno #5312
diff --git a/Lib/test/test_subprocess.py b/Lib/test/test_subprocess.py
index 5d3e040..2070495 100644
--- a/Lib/test/test_subprocess.py
+++ b/Lib/test/test_subprocess.py
@@ -535,7 +535,7 @@
             # Windows raises IOError
             except (IOError, OSError) as err:
                 if err.errno != 2:  # ignore "no such file"
-                    pass # XXX see #5312
+                    raise
 
     #
     # POSIX tests