I'm not particularly a fan of the idea of static converters to nix expressions, ala cabal2nix. They require someone to run them in the first place, so you don't

I'm not particularly a fan of the idea of static converters to nix expressions, ala cabal2nix. They require someone to run them in the first place, so you don't pick up updates to packages dynamically. I'd rather we collectively agree on a protocol for installing, updating, querying packages etc, such that each language-specific package manager can talk to others through a daemon and install foreign packages that are required for the projects. It would require a fair amount of work to update each package manager to talk it (optionally), and agree on the semantics and policies of the protocol, but I think the benefits could be huge. Using Nix/Guix as the basis for such protocol would probably be ideal due to the immutable nature of packages and ability to install side-by-side versions, and that you can specify an identity of a dependency, rather than rely on fuzzy matching of name and version.