anchor.diff:                 ) args2.flags );
       in removeAttrs
         (mergeAttrsByFuncDefaults ([args] ++ opts ++ [{ passthru = cfgWithDefaults; }]))
  -      ["flags" "cfg" "mergeAttrBy" "fixed" ]; # fixed may be passed as fix argument or such
  +      ["flags" "cfg" "mergeAttrBy" ];
   
   
     # deep, strict equality testing. This should be implemented as primop
  
positive.code:       && (eqListStrict (lib.attrValues a) (lib.attrValues b))
      else a == b; # FIXME !
  }
  
  
negative.code:   # };
    # will result in
    # { mergeAttrsBy = [...]; buildInputs = [ a b c d ]; }
    # is used by prepareDerivationArgs, defaultOverridableDelayableArgs and can be used when composing using
    # foldArgs, composedArgsAndFun or applyAndFun. Example: composableDerivation in all-packages.nix
    mergeAttrByFunc = x : y :
      let
  