RMAN-06004: Oracle error from recovery catalog database: RMAN-20005: target database name is ambiguous

The following errors occur in the trace file when duplicate a database:

MAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of Duplicate Db command at 05/13/2025 21:01:07
RMAN-05501: aborting duplication of target database
RMAN-06004: Oracle error from recovery catalog database: RMAN-20005: target database name is ambiguous
DBGMISC:           ENTERED krmkursr [21:01:13.976]
DBGMISC:           EXITED krmkursr [21:01:13.976] elapsed time [00:00:00:00.000]
-------------------------------------------------------------------------------
Trace Bucket Dump End: rman trace

RESOLUTION

If the source database is still running, the run the following the sql to get the dbid:

SQL>  select dbid, name from v$database;

      DBID NAME
---------- ---------
1234567890 TESTDB

Otherwise logon to RMAN catalog database, and

SQL>select rbs.db_key
         , rd.name
         , RBS.DB_ID
         , rbs.bs_key
         , rbs.recid
         , rbs.stamp
         , rbs.backup_type
         , rbs.start_time, status
      from rc_backup_set rbs, rc_database rd
     where rbs.db_key=rd.db_key
       and rbs.db_id=rd.dbid
       and rd.name='TESTDB' ;   

  DB_KEY NAME          DB_ID     BS_KEY      RECID      STAMP B START_TIM S
---------- -------- ---------- ---------- ---------- ---------- - --------- 
  86602789 TESTDB 1234567890  104349946       5934 1201017848 L 13-MAY-25 A

Finally, in RMAN script add the following:

set dbid=1234567890;
duplicate database from testdb to devdb until time "TO_DATE('2025-05-05 09:00:00','YYYY-MM-DD HH24:MI:SS'