BEGIN TRY;
  DBCC CHECKALLOC (tempdb);
  DBCC CHECKCATALOG (tempdb);
  PRINT 'No errors';
END TRY
BEGIN CATCH;
  PRINT 'Error';
END CATCH;

The check statement was aborted. DBCC CHECKALLOC cannot be run on TEMPDB.
DBCC execution completed. If DBCC printed error messages, contact your system administrator.
The check statement was aborted. DBCC CHECKCATALOG cannot be run on TEMPDB.
DBCC execution completed. If DBCC printed error messages, contact your system administrator.
No errors

Far away is close at hand in the images of elsewhere.

Anon.