How to add a flake package to system configuration

NobbZ · August 10, 2021, 4:57am

I do not really understand it, though thats what I read from this comment, which one eventually ends up reading if one follows the implementation of nixosSystem:

github.com

NixOS/nixpkgs/blob/53bd44342d22b53677b245c15de6e8f8a37718d0/lib/modules.nix#L65-L69


      
          , # This should only be used for special arguments that need to be evaluated
            # when resolving module structure (like in imports). For everything else,
            # there's _module.args. If specialArgs.modulesPath is defined it will be
            # used as the base path for disabledModules.
            specialArgs ? {}

Also, I read somewhere, that extraArgs and specialArgs do not compose well and forbid the use of _module.args, while one can use _module.args in many modules and it will properly merge.

If it is just for one or two packages, I tend to do it like this and write the attributes out fully. If it is more than that I use let or with with a narrow scope.