fix: explicitly mention pkgs as module argument

[korrat]

The previous change made in PR #31 caused failures when depending on pkgs in modules captured by haumea. This is due to the behaviour of nixpkgs.lib.nixos.evalModules which does not look up all arguments but only those captured by name explicitly, in addition to config, options, and lib passed by default.

This patch fixes those failures by explicitly making pkgs part of the argument list for the module returned by load, so that evalModules applies the correct argument list.

[korrat]

I have tested this with https://github.com/Lord-Valen/configuration.nix, replacing all the FIXMEs. No errors there.

[blaggacao]

I think a module system without pkgs is at least conceivable, so we should preemptively do pkgs ? {}

[blaggacao]

@whs-dot-hk what's your thought, here?

[whs-dot-hk]

Yes, I think so, with a default {} is better

[korrat]

That wouldn't work, because applyModuleArgs would fail. You cannot specify default arguments for module functions: NixOS/nixpkgs#243303.

[korrat]

That wouldn't work, because applyModuleArgs would fail. You cannot specify default arguments for module functions: NixOS/nixpkgs#243303.

[blaggacao]

Wow! Thanks for curating the reference here.

[whs-dot-hk]

Nice, can confirm the default do nothing (such as for pkgs) with mytest, when there is no config._module.args.mytest = "test"; there will be an error even a default "" is given (mytest ? "")

[whs-dot-hk]

I also think transformer with default

with haumea.lib.transformers; [
            liftDefault
            (hoistLists "_imports" "imports")
          ]

would be great if it can pass down from findLoad wdyt?

[korrat]

I also think transformer with default

with haumea.lib.transformers; [
            liftDefault
            (hoistLists "_imports" "imports")
          ]

would be great if it can pass down from findLoad wdyt?

Sounds like a good idea. I've seen a few hives which created custom overrides of load/findLoad just to adjust the transformer. For these use cases, allowing an override would certainly be beneficial.

Perhaps the loader could be treated similarly? Have it default to scopedImport and allow overriding for flexibility.

However, I wouldn't include those changes as part of a quick fix PR. Maybe we include it in the load refactor in #33, instead?

[blaggacao]

Yeah, let's go step by step. Merging... Thx!