current situation
I'm sorry to have to be so honest, but the project is currently in a disastrous state... There is no release branch and the dev branch is a work in progress.
workaround
I'm currently cherry-picking patches from various websites, distributions, and PRs in order to build an old version of the project. It is not possible to publish this without violating licenses.
solution
Would it be possible to derive a stable release branch of the last compatible version? I'll try to do that with a PR, but I would be happy if the project maintainers would accept it.
famous last words
The Mapnik binding for Python is still important for the cartography world and has been my companion for over 13 years. Please don't let it die this way.