anchor.diff:              in
                 throw "The option `${showOption loc}' in `${firstOption._file}' is a prefix of options in `${firstNonOption._file}'."
             else
  -            mergeModules' loc decls defns);
  +            mergeModules' loc decls defns) declsByName;
   
         matchedOptions = mapAttrs (n: v: v.matchedOptions) resultsByName;
   
  
positive.code:     elem
      filter
      findFirst
      flip
      foldl
      foldl'
      getAttrFromPath
  
negative.code:           [{ inherit (module) file; inherit value; }]
          ) configs;
  
        resultsByName = mapAttrs (name: decls:
          # We're descending into attribute ‘name’.
          let
            loc = prefix ++ [name];
  