Can you give some concrete examples of the issues with using a setup.py/DSL? I've only been using python intermittently for a few years and I'm probably not exposed to these things. Am I setting myself up for a fall by using setup.py?
I've seen setup.pys that read random files from the filesystem. I've seen setup.pys that shell out to random system commands that may or may not be installed. It's just a horrible format for what it's trying to accomplish.. because it's not a format! It's a programming language.
Not as such, but I've encountered setups that shell out to Inkscape, ImageMagick and other tools, and don't gracefully handle failure, sometimes to the point where the only error is "Failed to install egg".