the data being used in the loop and try to determine why the loop does
not exit when it should.
+You can also trying sending Emacs SIGUSR2, which, if `debug-on-event'
+has its default value, will cause Emacs to attempt to break it out of
+its current loop and into the Lisp debugger. This feature is useful
+when a C-level debugger is not conveniently available.
+
** If certain operations in Emacs are slower than they used to be, here
is some advice for how to find out why.