Concrete example: I frequently want to use the Jetbrains EAP IDEs. The EAP/Beta/RC are not in nixpkgs. Would there be interest of including this? This is fairly easy I think, but would require someone to make a PR each time a new version is released (I could volunteer to do make the PR and run the update script when new versions are released). (I currently use an overlay to have them available).
However, since I’m new to Nix/NixOS/Nixpkgs, I thought I’d ask before creating a PR (also apologies if this is not the right place for this question).
We try to package the latest stable release of any package as the main one. If you want something more bleeding edge, you could make a new attrpath that suffixes the version information.
There are a some things like this in nixpkgs; usually there’s a package variant like -unstable or -nightly or similar (depending on upstream naming). Take a look at KiCad. Or there’s an overlay that does the same kind of thing, like oxalica for Rust compiler toolchains.
That was easier for me as to think about attrpath or understanding default.nix of KiCad. But I leave that as future work for me or other interested persons.