anchor.diff:        };
   
         user = mkOption {
  -        type = types.nullOr types.string;
  +        type = types.nullOr types.str;
           default = null;
           description = "Specifies the user to log in as.";
         };
   
         hostname = mkOption {
  -        type = types.nullOr types.string;
  +        type = types.nullOr types.str;
           default = null;
           description = "Specifies the real host name to log into.";
         };
  
positive.code:       };
  
        identityFile = mkOption {
          type = types.nullOr types.string;
          default = null;
          description = ''
            Specifies a file from which the user identity is read.
  
negative.code:     };
  
      controlPath = mkOption {
        type = types.str;
        default = "~/.ssh/master-%r@%h:%p";
        description = ''
          Specify path to the control socket used for connection sharing.
  