Let's suppose I have a project that depends on packages that should only be installed via the systems package manager (e.g. bindings to C libraries), so that install_requires is not working.
Currently, I try to import said packages in setup.py and call sys.exit() with a positive exit code if the import fails. Is this good practice or are there better ways to accomplish this?
You can create native system packages (deb, rpm, etc.) and describe the dependencies in it (which are the C libraries in your case). You can check the Debian packages packing manual (or packages for some other manager, depending on the system you're using).