I have the pleasure of maintaining a reasonably popular -sys crate, and getting it working on Windows is an absolute nightmare, especially considering the competing toolchains & ABIs (msvc and gnu) and millions of ways the C dependency can be installed (it’s a big one, and users may choose a specific version, so we don’t bundle it), with no pkg-config telling you where to look.

No idea how build.rs being able to run any Rust code is an advantage, it’s not like setup.py can’t run any Python code and shell out. In fact, bespoke code capable of spitting out inscrutable errors during `setup.py install` is the old way that newer tooling tries to avoid. Rust evangelism is puzzling.