I made two demo implementations of Gentoo-like use-flags (Standard gentoo-like "use" flags across nixpkgs · Issue #12877 · NixOS/nixpkgs · GitHub) for nixpkgs:
- Undesirable one [Demo] splice.nix: poor man's implementation of Gentoo-like use-flags by oxij · Pull Request #56109 · NixOS/nixpkgs · GitHub
- The, IMHO, desirable one [Demo, RFC] Gentoo-like use-flags by oxij · Pull Request #56110 · NixOS/nixpkgs · GitHub that needs some more work (and, hence, consensus on merging that work to nixpkgs in the first place).
[Demo, RFC] Gentoo-like use-flags by oxij · Pull Request #56110 · NixOS/nixpkgs · GitHub also has all the technical details and thoughts on the topic.
Any thoughts are welcome here or there.