BUG 12.1.0.2 rman checksyntax not reliable

There is no syntax error reported but backup will fail.
Can you spot where the error is at?

[oracle@racnode-dc1-1 backup]$ rman checksyntax @ bkupinc0.rman

Recovery Manager: Release 12.1.0.2.0 - Production on Thu Nov 23 17:14:31 2017

Copyright (c) 1982, 2014, Oracle and/or its affiliates.  All rights reserved.

RMAN> connect target;
2> set echo on
3> set command id to "LEVEL0";
4> show all;
5> run {
6> set controlfile autobackup format for device type disk to '/sf_working/backup/%d_%I_%F.ctl';
7> allocate channel d1 device type disk format '/sf_working/backup/%d_%I_%T_%U.LEVEL0' MAXPIECESIZE 512 M MAXOPEMFILES 1;
8> backup as compressed backupset
9> incremental level 0 check logical database
10> filesperset 1 tag="LEVEL0"
11> tag="LEVEL0"
12> plus archivelog
13> filesperset 8 tag="LEVEL0"
14> tag="LEVEL0"
15> ;
16> alter database backup controlfile to trace as '/sf_working/backup/cf_@.sql' REUSE RESETLOGS;
17> create pfile='/sf_working/backup/init@.ora' from spfile;
18> }
19> report schema;
20> list backup summary;
21> exit
The cmdfile has no syntax errors

Recovery Manager complete.
[oracle@racnode-dc1-1 backup]$