This macro allows the end user to specify a particular Emacs executable via a configure script command-line arg. For example:
It also arranges to mention env var EMACS in the ’./configure –help’ output. See info node "(autoconf) Generic Programs" for details.
If env var EMACS is set, try to use its value directly, but avoid getting fooled by value ’t’ (set by older Emacsen for subprocesses). If no joy from the environment, search for "emacs" via AC_CHECK_PROG. If still no joy, display "Emacs not found; required!" and make configure exit failurefully. Otherwise, set shell var EMACS and AC_SUBST it, too.
Copyright © 2016-2017 Thien-Thi Nguyen
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