Variable: compilation-always-kill
compilation-always-kill is a customizable variable defined in
compile.el.gz.
Value
nil
Documentation
If t, always kill a running compilation process before starting a new one.
If nil, ask to kill it.
This variable was added, or its default value changed, in Emacs 24.3.
Probably introduced at or before Emacs version 24.3.
Source Code
;; Defined in /usr/src/emacs/lisp/progmodes/compile.el.gz
(defcustom compilation-always-kill nil
"If t, always kill a running compilation process before starting a new one.
If nil, ask to kill it."
:type 'boolean
:version "24.3")