Variable: debug-on-event

debug-on-event is a customizable variable defined in keyboard.c.

Value

sigusr2

Documentation

Enter debugger on this event.

When Emacs receives the special event specified by this variable, it will try to break into the debugger as soon as possible instead of processing the event normally through special-event-map.

Currently, the only supported values for this variable are sigusr1 and sigusr2.

This variable was added, or its default value changed, in Emacs 24.1.

View in manual

Probably introduced at or before Emacs version 24.1.

Source Code

// Defined in /usr/src/emacs/src/keyboard.c
  DEFVAR_LISP ("debug-on-event",
               Vdebug_on_event,
               doc: /* Enter debugger on this event.
When Emacs receives the special event specified by this variable,
it will try to break into the debugger as soon as possible instead
of processing the event normally through `special-event-map'.

Currently, the only supported values for this
variable are `sigusr1' and `sigusr2'.  */);