Subject: bug#11000: 24.0.94; Caching '--dired' is a bad idea

From: Glenn Morris <[email-masked]>
Date: Tue, 13 Mar 2012 19:47:42 -0400

Leo wrote:

> On 2012-03-13 00:47 +0800, Glenn Morris wrote:
>> Not caching it is a worse idea.
>
> Could you elaborate on this point? I really would like to know.

Just that it sounds very inefficient for everybody to have test what
options `ls' supports on every invocation, just because you are doing
something that sounds frankly rather odd.

There are many places in Emacs that test for features in external
commands the first time only, then make the IMO reasonable assumption
that the command isn't going to change underneath.
rmail-movemail-variant-in-use, find-exec-terminator, etc.