When running the MySQL test suite with a "debug" server (the DBUG facility is configured in) and the --debug command line option, the Debug Sync Facility writes trace messages to the DBUG trace. The following shell commands proved very useful in extracting relevant information:
egrep 'query:|debug_sync_exec:' mysql-test/var/log/mysqld.1.trace
It shows all executed SQL statements and all actions executed by synchronization points.
Sometimes it is also useful to see, which synchronization points have been run through (hit) with or without executing actions. Then add "|debug_sync_point:" to the egrep pattern.