Don't touch my shebang

Question

One thing I hate about distutils (I guess he is the evil who does this) is that it changes the shebang line. In other words, the more rational and environment-vars decided scripture

#!/usr/bin/env python 

gets magically converted into

#!/whatever/absolute/path/is/my/python 

This is seen also with grok: I used grokproject in a virtualenv to start my project, but now I cannot move the development directory around anymore, because it puts absolute paths in the shebang directive.

The reason why I ask this is twofold

• I want to move it around because I started developing in one directory (Experiments) and now I want to move it into a proper path, but I could not do it. So I created a new virtualenv and grokproject and copied my files. That fixes the issue, but leaves my curiosity for a more rational solution unsatisfied. In particular, if the reference to the virtualenv python interpreter was relative, the problem would not have been present in the first place. You know the layout of the virtualenv, and you can refer to the virtualenv python easily.
• The second reason is that I would like to be able to scp the virtualenv to another computer and run it there without trouble. This is not possible if you have hardcoded paths.

Answer 1

Of course you can move the development directory around. Distutils changes the paths to the python that you should run with when you run it. It's in Grok run when you run the buildout. Move and re-run the bootstrap and the buildout. Done!

Distutils changes the path to the Python you use to run distutils with. If it didn't, then you might end up installing a library in one python version, but when you try to run the script it would fail, because it would run with another python version that didn't have the library.

That's not insanity, it's in fact the only sane way to do it.

Update: If you know what you are doing, you can do this:

/path/to/install/python setup.py build -e "/the/path/you/want/python" install 

Make sure you clean the build directory first though. :)

Answer 2

Distutils will automatically replace the shebang with the location of the Python binary that was used to execute setup.py. To override this behavior you have two options:

Option 1: Manually

You may pass the flag --executable=/path/to/my/python to setup.py. Arguments are accepted.

Example:

% python setup.py build --executable=/opt/local/bin/python -d 

Option 2: Automatically

Your other option is to add a line to setup.cfg. If you aren't using setup.cfg, create it in the same directory as setup.py. Setup.py looks for this on startup. Any options specified here can still be overridden with flags at the command-line.

% cat setup.cfg  [build] executable = /opt/local/bin/python -d