[gentoo-user] Why does procmail need to know what my mailer is?

["Walter Dnes" <waltdnes@waltdnes.org>]

  I was emerging system and world on my laptop after a gcc upgrade.  I
"windowshaded" the xterm on my desktop that was ssh'd into the laptop.
All that was visible was the bar at the top of the window, with the
title indicating that emerge was working on procmail, item 85 of 95.  I
went away for a couple of hours, touched the shift key to wake up the
screen, and saw that emerge was still on procmail... WTF!?!?

  I opened the xterm and saw that the procmail build had an interactive
prompt, waiting for an answer from me...

> Could not find any mailer.  It should be a mailer accepting at least
> one plain destination address as its only argument (any sendmail
> compatible mailer will do), and the mail-to-be-sent on stdin.
> What is your mailer called?  (You can override this in config.h)

  I replied "oogabooga" and it went on its merry way.  I use ssmtp, but
I've made 1 tweak to my system.  Note the following *DIRECTORIES*...

[aa1][root][~] ll /usr/bin/sendmail
total 28
drwxr-xr-x 2 root root    72 Aug 12 19:07 .
drwxr-xr-x 3 root root 28240 Oct 12 06:36 ..
-rw-r--r-- 1 root root     0 Aug 12 19:07 .keep
[aa1][root][~] ll /usr/sbin/sendmail
total 2
drwxr-xr-x 2 root root   72 Aug 12 19:08 .
drwxr-xr-x 3 root root 2416 Oct 12 02:23 ..
-rw-r--r-- 1 root root    0 Aug 12 19:08 .keep
[aa1][root][~] ll /usr/lib64/sendmail
total 27
drwxr-xr-x  2 root root    72 Aug 12 19:08 .
drwxr-xr-x 46 root root 27464 Oct 12 02:26 ..
-rw-r--r--  1 root root     0 Aug 12 19:08 .keep
[aa1][root][~]

  My most embarressing incident involving linux was one day when I added
a cron job, and it started sending log messages to "root".  Back then, I
didn't know that ssmtp made a "sendmail" link, let alone 3 of them.
ssmtp did its thing, and pushed the messages for "root" to my ISP's MTA,
which forwarded them to my ISP's root inbox.  "They were not amused".

  After a few attempts, I finished the game of whack-a-mole and killed
all the symlinks, and made sure that it would never happen again.  I
addition to configuring ssmtp.conf to send "root" messages to myself, I
also made the above directories to prevent symlinks being constructed.
Who knows what other programs send mail on a whim.

  This is the first time I've had this interactive prompt happen with
procmail.  What gives?

-- 
Walter Dnes <waltdnes@waltdnes.org>