5.5 builds produced by buildbot or manually using default cmake parameters understand --debug and --disable-debug options, but fail to start as the options are ambiguous:

111227 18:18:38 [ERROR] maria-5.5/relwithdebinfo//sql/mysqld: ambiguous option '-disable-debug' (-disable-debug-abort-slave-event-count)
111227 18:18:38 [ERROR] Aborting

111227 18:18:47 [ERROR] maria-5.5/relwithdebinfo//sql/mysqld: ambiguous option '--debug' (debug-abort-slave-event-count, debug_no_thread_alarm)
111227 18:18:47 [ERROR] Aborting

 bzr version-info
revision-id: <email address hidden>
date: 2011-12-27 00:39:34 +0100
build-date: 2011-12-27 18:58:48 +0400
revno: 3189
branch-nick: maria-5.5

Not reproducible with MySQL 5.5.19 (if it's built with default cmake options, --debug is unknown there).