Python 3.12 shim script fails as a shebang line when called from a bash shell

[gregneagle]

Python scripts using #!/usr/local/bin/managed_python3 may fail to run as expected when called from a bash shell.
The following uses the "python_recommended_signed-3.12.1.80740.pkg" packaged release:

bash-3.2$ /usr/local/bin/managed_python3 -V
Python 3.12.1

bash-3.2$ cat test.py
#!/usr/local/bin/managed_python3
print("Hello, world!")

bash-3.2$ ./test.py 
./test.py: line 2: syntax error near unexpected token `"Hello, world!"'
./test.py: line 2: `print("Hello, world!")'

I'm guessing this same issue occurs with the 3.11 package as well.

(Same script works fine when called from a zsh shell:)

bash-3.2$ zsh
% ./test.py
Hello, world!

[erikng]

It's because the shim contains a shebang for zsh. How do you think we should handle this?

[erikng]

Also see

#55 and gregneagle/relocatable-python#31

[gregneagle]

No, the fact the shebang contains zsh is not the cause here. The behavior is the same if the shebang is #!/bin/sh

[gregneagle]

I think the only real approaches at this point are to either replace the shim with a small compiled binary, or remove the shim and symlink entirely and recommend people use #!/Library/ManagedFrameworks/Python/Python3.framework/Versions/Current/bin/python3 as the shebang.

Maybe, just maybe, we can get python.org to fix the upstream issues. Ideally, they would build the Python.framework in such a way that it could be relocated without us having to hack at it with the relocatable-python tool. Barring that, perhaps we could get them to at least fix the issue where it can't find the platform-specific libraries when the binary is called via a symlink.

[notverypc]

Is there anything us MacAdmins can do to help get python.org to fix the upstream issues?

[gregneagle]

FIle issues?

[gregneagle]

I think I have stumbled across a much better workaround for the Python 3.11+ issues. Instead of symlinking to Python.framework/Versions/Current/bin/python3, you make the symlink to Python.framework/Versions/Current/Resources/Python.app/Contents/MacOS/Python

This avoids the "Could not find platform dependent libraries <exec_prefix>" and does not require a shim script/executable.

[erikng]

Closing this as the latest pre releases contain this fix and initial testing looks fine.