MacOS `subprocess` raising: FileNotFoundError: /usr/sbin/sysctl

Question

I've suddenly started getting an error on all versions of Python on MacOS reporting the following when using subprocess:

FileNotFoundError: [Errno 2] No such file or directory: '/usr/sbin/sysctl -n machdep.cpu.brand_string'

However, /usr/sbin/sysctl does exist, I can run the command myself, under my normal user, without any issue - just not with a Python interpreter. When launching a Python interpreter owned by root I don't get this issue.

The permissions and ownership are reported as the following:

-rwxr-xr-x 1 root wheel 135296 Oct 28 09:43 /usr/sbin/sysctl*

Changing the permissions/ownership doesn't appear possible even undo sudo anyway; as Operation not permitted is reported.

Answer 1

There are extra limitations for applications which path those can read from. You must specifically allow certain paths to applications. I think this is why you can't open it from Python.

Another potential root cause might be that you do not use subprocess correctly.

Here is the correct way of using it:

import shlex
import subprocess
subprocess.run(shlex.split("/usr/sbin/sysctl -n machdep.cpu.brand_string"))
# Apple M1
# CompletedProcess(args=['/usr/sbin/sysctl', '-n', 'machdep.cpu.brand_string'], returncode=0)