[atiedebee]

Im very familiar with Nix or the language, but why would interpreting guile scheme for package management be expensive? What are guix and nix doing that would require evaluating everything lazily for good enough performance?

[Hasnep]

It's not the Nix/Guile that's expensive, it's situations like:

    let chromium = pkgs.chromium; in 1 + 1

In a maximally eager language you'd need to wait for the entirety of Chromium to build before you can find out what 1 + 1 is.

[atiedebee]

I checked the spec and Scheme R5RS does have lazy evaluation in the form of promises using "delay" and "force", but I can see why explicitly having to put those everywhere isn't a good solution.