Python distutils and non-standard script locations

[sawyl]

Winding down ahead of the start of my Christmas leave, I finally found the time to dig into a little side project to extend python distutils to allow me to bundle up various tools which install in non-standard locations — principally sbin and libexec directories.

After reading my way through the various commands included in distutils, I worked came up with a series of modules to deal with the problem:

• a build_sbin.py module that subclasses build_scripts, replacing the normal install location with a specific sbin version
• a install_sbin.py module that duplicates much of the functionality of install_scripts.py, picking up the targets from the sbin build directory and installing them into either the sbin directory under the standard installation or the value set in setup.cfg
• a dist.py module that subclasses distutils.dist.Distribution to create CustomDistribution, adding the attributes self.sbin and self.libexec to allow these keywords to be passed through from distutils.core.setup() and used by the custom build and install modules.

With all this in place, it was simply a matter adding the keyword distclass=CustomDistribution to setup() and adding the appropriate libraries to cmdclass — I eventually moved this into CustomDistribution even though I'm pretty sure it's not the right thing to do, because I thought I was going to want to do it every time.

This may all seem a bit baroque but got two significant bits of code that need to be installed in this fashion and I need something to reduce the complexity of the install processs and to provide a single command that can be used to regress the current version to an older one in the event of problems. And finally, after a morning of hackery, I think I've got something that will fulfil my requirements.