If you have proper package building rules (not this currently popular fpm nonsense, which produces broken RPMs and DEBs unless one puts much effort in using it)

If you have proper package building rules (not this currently popular fpm nonsense, which produces broken RPMs and DEBs unless one puts much effort in using it), tearing building procedure apart and adjusting it for other package managers will be really easy. No, you're not being an asshole. And if you want to be it even less, write a proper makefile and call that from package build rules (RPM spec, debian/rules, ebuild, or anything else).