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subprocess.call ('command.sh') returning error code 127 in django app while running ok in bash console

Hello, I need a django app to run a app. I installed the app (this one : https://cosma.arthurperret.fr/installing.html). It works fine while running in command line. But embedded in my django app, it does not work. subprocess.check_call returns :

subprocess.CalledProcessError: Command './cosma.sh' returned non-zero exit status 127.

I could not find answers in the other topics related to subprocess.call in the forum.

Thanks for any idea !

experience | 6 posts | March 17, 2026, 10:28 p.m. | permalink

You need to use the full path to the executable.

Staff glenn | 10440 posts | PythonAnywhere staff | March 18, 2026, 4:15 p.m. | permalink

Thank you for your answer. Even if I use the full path, it returns the same :

CalledProcessError at [view]

Command '[full path]/cosma.sh' returned non-zero exit status 127.

Any idea ?

experience | 6 posts | March 19, 2026, 7:07 a.m. | permalink

See https://help.pythonanywhere.com/pages/NoSuchFileOrDirectory/#use-absolute-not-relative-paths

Staff fjl | 5426 posts | PythonAnywhere staff | March 19, 2026, 6:13 p.m. | permalink

Thanks. The error occurs even while I am using absolute path.

experience | 6 posts | March 20, 2026, 6:48 a.m. | permalink

It looks like you just used the text [full path] instead of the actual path to the file. You need to use the actual path to the file, not a placeholder.

Staff glenn | 10440 posts | PythonAnywhere staff | March 21, 2026, 11:25 a.m. | permalink

No, I wrote full_path in this forum post, but in my code I did write the full path :

subprocess.check_call('/home/graphe/graphe/static/cosma/cosma.sh')

and the server returns an error :

subprocess.CalledProcessError: Command '/home/graphe/graphe/static/cosma/cosma.sh' returned non-zero exit status 127.

experience | 6 posts | March 21, 2026, 1:10 p.m. | permalink

That cannot be the correct full path. Your username is experience so, at the very least, the path needs to start with "/home/experience". If that is incorrect, then the rest may not be, too. Find the binary that you want to run and then use the path to the that in your code.

Staff glenn | 10440 posts | PythonAnywhere staff | March 21, 2026, 4:40 p.m. | permalink

I have another account, graphe, on eu.pythonanywhere.com. The error occurs on that account, with the full path.

The path to the binay is :

/home/graphe/.nvm/versions/node/v24.14.0/bin/cosma

The command I would like to launch is :

cosma modelize

Sorry if I am missing something. Thank you very much for your help

experience | 6 posts | March 21, 2026, 5:05 p.m. | permalink

If the path that you just specified is /home/graphe/.nvm/versions/node/v24.14.0/bin/cosma then you need to use that, and not /home/graphe/graphe/static/cosma/cosma.sh

Staff glenn | 10440 posts | PythonAnywhere staff | March 22, 2026, 11:59 a.m. | permalink

That did not work either.

I finally found a solution : to copy the env['PATH'] from the bash console to the subprocess command :

import os

env = os.environ.copy()

env['PATH']= '/home/graphe/.virtualenvs/bulle313/bin:/home/graphe/.local/bin:/home/graphe/.nvm/versions/node/v24.14.0/bin:/usr/local/julia-1.10.4/bin:/usr/lib/postgresql/16/bin/:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin'

subprocess.call(["/home/graphe/node_modules/.bin/cosma", "modelize"], cwd="/home/graphe/graphe/static/cosma", env=env)

It works !

experience | 6 posts | March 22, 2026, 2:25 p.m. | permalink