If a thread is cancelled (including if heat-engine is restarted) while a user hook (aka breakpoint) is active, the hook is still marked as active in the database. If the user modifies the environment to disable the hook, then the next time Heat reaches the point in traversing the stack where the hook was invoked Heat will pause and wait for the hook to be cleared; however there will be no log message to indicate that the hook was invoked, nor a corresponding event in the event list, nor any indication from the "hook-poll" command that the hook is active.