Subject: grep: warning: GREP_OPTIONS is deprecated; please use an alias or script

From: 積丹尼 Dan Jacobson <[email-masked]>
Date: Tue, 02 Dec 2014 07:01:43 +0800

(rgrep ...) gives
grep: warning: GREP_OPTIONS is deprecated; please use an alias or script
GNU Emacs 24.4.1