Eval-config.nix waging war against nixpkgs.pkgs?

Why does <nixos/lib/eval-config.nix> not honor modularily set nixpkgs.pkgs for use in the pkgs arguments of modules?
Even though

is not set on the caller?

When evaluating a modularily set version of packages with an eval config of a different version, then I get an evaluation conflict, for example here:


giving proof of en environment in which the module’s nixpkgs is based on the new version while pkgs is an old version.

If I use eval-config.nix off the same version, then there is no version mismatch.

I can’t see where eval-config does this magic (in the case that it’s own pkgs argument is null).

Any pointer?

I’m parsing this
to be evaluated to [] in this case.
Next, I’m parsing that this
would set it to my modularly set pkgs version.

But the error suggests there is at least one instantiation involved with a version mismatch. Why?

Is laziness broken? :crying_cat_face: