anchor.diff:    imports = [
       (mkRemovedOptionModule [ "services" "mysql" "pidDir" ] "Don't wait for pidfiles, describe dependencies through systemd.")
       (mkRemovedOptionModule [ "services" "mysql" "rootPassword" ] "Use socket authentication or set the password outside of the nix store.")
  +    (mkRemovedOptionModule [ "services" "mysql" "extraOptions" ] "Use services.mysql.settings.mysqld instead.")
     ];
   
     ###### interface
  
positive.code:   ###### implementation
  
    config = mkIf config.services.mysql.enable {
  
      warnings = optional (cfg.extraOptions != null) "services.mysql.`extraOptions` is deprecated, please use services.mysql.`settings`.";
  
      services.mysql.dataDir =
        mkDefault (if versionAtLeast config.system.stateVersion "17.09" then "/var/lib/mysql"
  
negative.code:       };
  
        settings = mkOption {
          type = format.type;
          default = {};
          description = ''
            MySQL configuration. Refer to
  