Warning log printed when merging again after waiting for merge completion in alter.merge_verify test case on macOS

Environment

• Version: seekdb (OceanBase seekdb) source revision 1-86c590552f3c2eddc234225b5611a800d8f71898
• Build Branch: master
• Build Time: May 11 2026 20:36:48
• Build Flags: RelWithDebInfo

./bin/seekdb -V
Starting seekdb (OceanBase seekdb) source revision 1-86c590552f3c2eddc234225b5611a800d8f71898.
(null) (OceanBase seekdb)

REVISION: 1-86c590552f3c2eddc234225b5611a800d8f71898
BUILD_BRANCH: master
BUILD_TIME: May 11 2026 20:36:48
BUILD_FLAGS: RelWithDebInfo
BUILD_INFO:

Copyright (c) 2011-present OceanBase Inc.

Description / Steps to Reproduce

The alter.merge_verify test case prints a warning log when executing a merge again after waiting for the previous merge to complete.

Reproduction Commands:

obd test mysqltest test_env \
  --mysqltest-bin=${OCEANBASE_HOME}/deps/3rd/u01/obclient/bin/mysqltest \
  --obclient-bin=${OCEANBASE_HOME}/deps/3rd/u01/obclient/bin/obclient \
  --init-only \
  --init-sql-dir=${OCEANBASE_HOME}/tools/deploy \
  --init-sql-files='init.sql,init_user.sql|root@sys|test'

obd test mysqltest test_env \
  --mysqltest-bin=${OCEANBASE_HOME}/deps/3rd/u01/obclient/bin/mysqltest \
  --obclient-bin=${OCEANBASE_HOME}/deps/3rd/u01/obclient/bin/obclient \
  --disable-reboot \
  --test-set=alter.merge_verify

Warning Log Screenshot:

Additional Context

• This issue was introduced after March 31, 2026.
• The issue was observed on a Mac system.
• For internal mapping of target branch and iteration properties, refer to: https://work.oceanbase-dev.com/automerge/iteration-branch-map

Start with the alter.merge_verify test case and run it using the provided obd test mysqltest commands on macOS. Trace the warning produced when a merge is executed again after the previous merge completes; done means the test no longer prints the inappropriate warning and still passes.