subprocess.Popen() suddenly giving me grief?

Python Help
1 
C:\Program Files (x86)\Microsoft Visual Studio\2019\Community>python3
Python 3.10.11 (tags/v3.10.11:7d4cc5a, Apr  5 2023, 00:38:17) [MSC v.1929 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import subprocess
>>> subprocess.Popen(['Z:/depot/kJams/Scripting/AutoPin.exe', 'parameter'])
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.10_3.10.3056.0_x64__qbz5n2kfra8p0\lib\subprocess.py", line 971, in __init__
    self._execute_child(args, executable, preexec_fn, close_fds,
  File "C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.10_3.10.3056.0_x64__qbz5n2kfra8p0\lib\subprocess.py", line 1456, in _execute_child
    hp, ht, pid, tid = _winapi.CreateProcess(executable, args,
OSError: [WinError 50] The request is not supported

this was working recently. this is on Windows 10 with all latest OS updates

problem may have started after recent OS update?

2

What kind of device is your Z: drive?

3

it is a network mapped drive. but i have added it to the local intranet zone

Screenshot 2023-12-13 at 1.46.55 PM
Screenshot 2023-12-13 at 1.46.55 PM1920Ă—1763 258 KB

4

Was this network mapped drive, and the Python code, previously being used on the same computer?

A bit of searching around suggests that this error (from Windows) might be something to do with trying to launch a 32-bit executable on a 64-bit platform or vice-versa.

5

it was previously in a Parallels VM where the host machine was serving up the network mapped Z drive, via the Parallels driver, but now the Z drive is hosted on a different machine. I figured it would make no difference, except for allowing Z in the local intranet

6

i launched a 32bit command line (from vs 2008) tried the same thing and same problem.
this was working literally just 2 days ago. only difference is the new drive and a software update

7

If you try using the exact same code to invoke something that’s local to your C: drive, does it work? Would be an easy way to see whether it’s the network drive that’s causing issues.

8

you’re right, it DID work when run from a local drive.
this is vexing

9

Okay, that’s definitely of interest. Sorry though: I’ve just come to the end of my knowledge of Windows limitations. So I’ll have to let someone else figure out exactly WHY a network drive causes you grief here.

10

when i move the AutoPin.exe to an internal drive, it DOES work. so it has something to do with the fact that it’s on a network-mapped drive. but see my screen shot where you can see that i EXPLICITLY allow running apps from that drive

11

After a little research, I guess It is a problem about “Mapped Device”
The exception is caused by “_winapi.CreateProcess” that is a windows system call.

it says “Mapped drives are per session” and maybe just the python is just out of user session .
Maybe, you can try “UNC path” or use a true file system like “NFS”

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12

you’re correct. using UNC paths fixes the problem.

separately, another viable fix is to use the EnableLinkedConnections registry key, which is what i did on my system.

1 Like