anchor.diff:                    opt.name
                     (opt.merge list);
                 options =
  -                let path = decl.type.docPath opt.name; in
  +                let path = opt.type.docPath opt.name; in
                   (lib.fix
                     (fixableMergeFun (recurseInto path) (optionConfig []))
                   ).options;
  
positive.code:     in
        foldl (opt: f: f opt) init [
          # default settings
          mergeFromType
  
          # user settings
          addDeclaration
  
negative.code:           in
              opt // {
                merge = list:
                  opt.type.iter
                    (path: opts:
                      (lib.fix
                        (fixableMergeFun (recurseInto path) (optionConfig opts))
  