Revert "applyPatches: to extendMkDerivation, fix meta.position"

      ];

    }

  */

  applyPatches = lib.extendMkDerivation {

    constructDrv = stdenvNoCC.mkDerivation;

    extendDrvArgs =

      finalAttrs:

  applyPatches =

    {

      src,

      name ?

        (

          if builtins.typeOf src == "path" then

            baseNameOf src

          else if builtins.isAttrs src && builtins.hasAttr "name" src then

            src.name

          else

            throw "applyPatches: please supply a `name` argument because a default name can only be computed when the `src` is a path or is an attribute set with a `name` attribute."

        )

        + "-patched",

      patches ? [ ],

      prePatch ? "",

      postPatch ? "",

      ...

    }@args:

    assert lib.assertMsg (

    assert lib.assertMsg (

      !args ? passthru

    ) "applyPatches will not merge 'passthru', change it in 'src' instead";

    if patches == [ ] && prePatch == "" && postPatch == "" then

      src # nothing to do, so use original src to avoid additional drv

    else

      let

        keepAttrs = names: lib.filterAttrs (name: val: lib.elem name names);

        # enables tools like nix-update to determine what src attributes to replace

        extraPassthru = lib.optionalAttrs (lib.isAttrs finalAttrs.src) (

        extraPassthru = lib.optionalAttrs (lib.isAttrs src) (

          keepAttrs [

            "rev"

            "tag"

            "url"

            "outputHash"

            "outputHashAlgo"

          ] finalAttrs.src

          ] src

        );

      in

      stdenvNoCC.mkDerivation (

        {

        name =

          args.name or (

            if builtins.isPath finalAttrs.src then

              baseNameOf finalAttrs.src + "-patched"

            else if builtins.isAttrs finalAttrs.src && (finalAttrs.src ? name) then

              let

                srcName = builtins.parseDrvName finalAttrs.src.name;

              in

              "${srcName.name}-patched${lib.optionalString (srcName.version != "") "-${srcName.version}"}"

            else

              throw "applyPatches: please supply a `name` argument because a default name can only be computed when the `src` is a path or is an attribute set with a `name` attribute."

          );

        # Manually setting `name` can mess up positioning.

        # This should fix it.

        pos = builtins.unsafeGetAttrPos "src" args;

          inherit

            name

            src

            patches

            prePatch

            postPatch

            ;

          preferLocalBuild = true;

          allowSubstitutes = false;

        dontConfigure = true;

        dontBuild = true;

        doCheck = false;

          phases = "unpackPhase patchPhase installPhase";

          installPhase = "cp -R ./ $out";

        # passthru the git and hash info for nix-update, as well

        # as all the src's passthru attrs.

        passthru = extraPassthru // finalAttrs.src.passthru or { };

        }

        # Carry (and merge) information from the underlying `src` if present.

        # If there is not src.meta, this meta block will be blank regardless.

        meta = lib.optionalAttrs (finalAttrs.src ? meta) removeAttrs finalAttrs.src.meta [ "position" ];

      };

  };

        // (optionalAttrs (src ? meta) {

          inherit (src) meta;

        })

        // (optionalAttrs (extraPassthru != { } || src ? passthru) {

          passthru = extraPassthru // src.passthru or { };

        })

        # Forward any additional arguments to the derivation

        // (removeAttrs args [

          "src"

          "name"

          "patches"

          "prePatch"

          "postPatch"

        ])

      );

  # TODO: move docs to Nixpkgs manual

  # An immutable file in the store with a length of 0 bytes.