`gh pr list` stderr is not captured by subprocess

Python Help
1

gh pr list stderr is not captured by subprocess. I am not sure github cli gh has a special implementation of stderr.

(base) root@ip-172-26-1-210:# python -c "import subprocess;print(subprocess.run('gh pr list', shell=True, capture_output=True))"
CompletedProcess(args='gh pr list', returncode=0, stdout=b'', stderr=b'')
(base) root@ip-172-26-1-210:~/github# python --version
Python 3.10.10
(base) root@ip-172-26-1-210:~/github# gh pr list
no open pull requests in peterjpxie/github
(base) root@ip-172-26-1-210:~/github# gh pr list 2>a.txt
(base) root@ip-172-26-1-210:~/github# cat a.txt
no open pull requests in peterjpxie/github

Environment:
Ubuntu 20.04
Miniconda base env: Python 3.10.10

2

Maybe gh is detecting if you are on a tty device.
What happens if you do:

gh pr list </dev/null
gh pr list 2>&1 | cat
3 
# gh pr list </dev/null
no open pull requests in peterjpxie/github
# gh pr list 2>&1 | cat
<no output>
#
4

That is what your subprocess call is doing.

As a machine interface I think its designed to only return pr info if there is some.
That makes your code simpler as you do not need to special case the no pr message.

5

Thanks, Barry!