jit-lock-debug-mode
jit-lock-debug-mode is an interactive compiled Lisp function in `jit-lock.el
'.
(jit-lock-debug-mode &optional ARG)
Minor mode to help debug code run from jit-lock.
When this minor mode is enabled, jit-lock runs as little code as possible
during redisplay and moves the rest to a timer, where things
like `debug-on-error' and Edebug can be used.