anchor.diff:        })) from);
   
         config = {
  -        warnings = filter (x: x != "") (map (f:
  -          let val = getAttrFromPath f config;
  -              opt = getAttrFromPath f options;
  -          in
  -          optionalString
  -            (val != "_mkMergedOptionModule")
  -            "The option `${showOption f}' defined in ${showFiles opt.files} has been changed to `${showOption to}' that has a different type. Please read `${showOption to}' documentation and update your configuration accordingly."
  -        ) from);
  +        _module.assertions =
  +          let warningMessages = map (f:
  +            let val = getAttrFromPath f config;
  +                opt = getAttrFromPath f options;
  +            in {
  +              ${showOption f} = {
  +                enable = mkDefault (val != "_mkMergedOptionModule");
  +                type = "warning";
  +                message = "The option `${showOption f}' defined in ${showFiles opt.files} has been changed to `${showOption to}' that has a different type. Please read `${showOption to}' documentation and update your configuration accordingly.";
  +              };
  +            }
  +            ) from;
  +          in mkMerge warningMessages;
         } // setAttrByPath to (mkMerge
                (optional
                  (any (f: (getAttrFromPath f config) != "_mkMergedOptionModule") from)
  
positive.code:         visible = false;
          apply = x: throw "The option `${showOption optionName}' can no longer be used since it's been removed. ${replacementInstructions}";
        });
        config.assertions =
          let opt = getAttrFromPath optionName options; in [{
            assertion = !opt.isDefined;
            message = ''
              The option definition `${showOption optionName}' in ${showFiles opt.files} no longer has any effect; please remove it.
              ${replacementInstructions}
            '';
          }];
      };
  
    /* Return a module that causes a warning to be shown if the
  
negative.code:       });
        config = mkMerge [
          {
            _module.assertions.${showOption from} = {
              enable = mkDefault (warn && fromOpt.isDefined);
              type = "warning";
              message = "The option `${showOption from}' defined in ${showFiles fromOpt.files} has been renamed to `${showOption to}'.";
            };
          }
          (if withPriority
            then mkAliasAndWrapDefsWithPriority (setAttrByPath to) fromOpt
  