Is there document about override with a function?

vccs · April 21, 2023, 4:09am

I just learn that the override function can take a function as input to override the original args.

NixOS/nixpkgs/blob/519e7870b6b85262d3efc726f337bd0a4e8b8efa/pkgs/top-level/all-packages.nix#L171


      
            if x ? deepOverride then (x.deepOverride newArgs) else
            if x ? override then (x.override newArgs) else
            x) else x;
            
          # usage: (you can use override multiple times)
          # let d = makeOverridable stdenv.mkDerivation { name = ..; buildInputs; }
          #     noBuildInputs = d.override { buildInputs = []; }
          #     additionalBuildInputs = d.override ( args : args // { buildInputs = args.buildInputs ++ [ additional ]; } )
          makeOverridable = f: origArgs: f origArgs //
            { override = newArgs:
                makeOverridable f (origArgs // (if builtins.isFunction newArgs then newArgs origArgs else newArgs));
              deepOverride = newArgs:
                makeOverridable f ((lib.mapAttrs (deepOverride newArgs) origArgs) // newArgs);
              origArgs = origArgs;
            };
          
          

          
### STANDARD ENVIRONMENT
          
          

          
allStdenvs = import ../stdenv {

But it’s not documented in Nixpkgs 23.11 manual | Nix & NixOS.

fricklerhandwerk · April 21, 2023, 7:15am

Yes, thanks for pointing it out. Please open an issue or make a pull request to add something at all.