Calling subprocess Popen, call, or check_output while running a python windows exe created with pyinstaller --noconsole results in an error with the following stack:
...
File "subprocess.py", line 566, in check_output
File "subprocess.py", line 702, in __init__
File "subprocess.py", line 823, in _get_handles
WindowsError: [Error 6] The handle is invalid
Came across this issue but no direct answer, so creating this post to hopefully make the solution easier to find.
I found an answer here by Alastair McCormack (thanks!!!!). Turns out the issue is that subprocess fails to properly resolve default stdin/out.
Copied for posterity:
Line 1117 in subprocess.py is:
p2cread = _winapi.GetStdHandle(_winapi.STD_INPUT_HANDLE)
which made me suspect that service processes do not have a STDIN associated with them (TBC)
This troublesome code can be avoided by supplying a file or null device as the stdin argument to popen.
In Python 3.3, 3.4, and 3.5, you can simply pass stdin=subprocess.DEVNULL. E.g.
subprocess.Popen( args=[self.exec_path], stdout=subprocess.PIPE, stderr=subprocess.STDOUT, stdin=subprocess.DEVNULL)
In Python 2.x, you need to get a filehandler to null, then pass that to popen:
devnull = open(os.devnull, 'wb')
subprocess.Popen( args=[self.exec_path], stdout=subprocess.PIPE, stderr=subprocess.STDOUT, stdin=devnull)
