Based on the recent discussions around %fedora/%rhel macros and ELN, and %bcond generally being confusing to work with, I came up with a distribution-wide feature that defines generic feature keywords and associated helper macros that packages can check in build-time conditionals.
The key advantage here is the defaults are defined by the buildroot, not the package. The package is just a building block.
I'd like some input to improve this and unless this turns out to be a really bad idea, I intend to submit it as a change proposal. Even though the more packages use it the more beneficial it gets, it's, of course, perfectly optional.
Details in the gist: https://gist.github.com/contyk/0aaaaf0585c57976ca18a293b3566408
Cheers, P