Subject: Re: bug#13413: 24.2.92; Didn't find `rmail-summary-line-count-flag'
From: Eli Zaretskii <[email-masked]>
To: Xue Fuqiao <[email-masked]>
Cc: [email-masked]
Date: Fri, 11 Jan 2013 16:22:33 +0200
List-Id: <debbugs-submit.debbugs.gnu.org>

> Date: Fri, 11 Jan 2013 21:56:53 +0800
> From: Xue Fuqiao <[email-masked]>
> 
> In (info "(emacs) Rmail Make Summary"):
> 
> The variable `rmail-summary-line-count-flag' controls whether the
> summary line for a message should include the line count of the message.
> 
> I couldn't find this variable after I required the `rmail' package.

You need to require rmailsum.  (The "rmail-summary" part hints at
that.)  Rmail is not all defined on a single rmail.el file, there are
a few more.

Closing.