anchor.diff:    inherit (nixpkgs) lib;
   in
   
  -{ env, packageNames, tools ? _: [], shellToolOverrides ? _: _: {} }:
  +{ envFunc, packageNames, tools ? _: [], shellToolOverrides ? _: _: {} }:
   
   let
     inherit (builtins) listToAttrs filter attrValues all concatLists;
  
positive.code:   pname = "work-on-multi--combined-pkg";
    version = "0";
    license = null;
  })).env;
  
negative.code:     })).out;
      notInTargetPackageSet = p: all (pname: (p.pname or "") != pname) packageNames;
      baseTools = generalDevTools' {};
      env = envFunc reflex-platform;
      overriddenTools = baseTools // shellToolOverrides env baseTools;
      depAttrs = lib.mapAttrs (_: v: filter notInTargetPackageSet v) (concatCombinableAttrs (concatLists [
        (map getHaskellConfig (lib.attrVals packageNames env))
  