Issue 3905: subprocess failing in GUI applications on Windows - Python tracker

I'm getting a 'The handle is invalid' error when using subprocess.Popen in Python 2.5 (and 2.6). If any of the stdio handles are somehow invalid or not real io handles (fd is not 0, 1 or 2), and you are not telling subprocess to PIPE all of the handles, then subprocess throws the following exception. The easiest way to reproduce this is using run PythonWin from a Windows Command Prompt: C:\Python\