Manuel, For years I see developers trying to export problems from the source domain over to some other domain because they don't want to fix the problem at its source. And this ends up creating unnecessary dependencies in software which makes it brittle and difficult to evolve the software. What you are proposing is an example of people "throwing things over the fence". This is a bad practice. In this particular instance the SOURCE of the problem is 'setuptools' naming conventions. And therefore the solution needs to be taken in setuptools. By taking problems like this and throwing them over the fence, you create more problems by making the software more tightly coupled, with more dependencies, and that makes software brittle and easily broken, hard to maintain, difficult of evolve.
As far as offering alternative solutions to your patch. I've already done that but you want to ignore them. Here's the two solutions: 1. Go fix the problem in 'setuptools'. 2. Put your string rewriter into an extension that overrides bdist_rpm and call it from a special commandline option. This way it's in Distutils but does not impact every user. Those that need it can call it using the commandline option.