#484 MH-E should not whine if no MH is found when compiling Emacs

[Mike Kupfer]

If you build Emacs without having any MH variant installed, you get this message

No MH variant found on the system

The message appears multiple times (including once when compiling Gnus); it clutters up the build log for no good reason. MH-E should only warn if someone tries to actually use it and no MH variant can be found at that time.

RMS and Stefan Monnier have both called this out as a bug (see the thread starting at http://lists.gnu.org/archive/html/emacs-devel/2016-04/msg00077.html).

[Mike Kupfer]

Forgot to mention: I've reproduced this with Emacs 25.1-rc1.

[Mike Kupfer]

The message comes from the mh-variant-set call in the :set method for mh-variant.

[Mike Kupfer]

This was fixed with a series of changesets starting with

commit 2dc909c67b987e20cbfd4816cb4264151c68f2f9
Author: Glenn Morris <rgm@gnu.org>
Date:   Wed Mar 7 22:56:23 2018 -0800

    Suppress "No MH variant found" message (bug#30669)

* lisp/mh-e/mh-e.el (mh-variant): Don't try to detect till needed.
* lisp/mh-e/mh-e.el (mh-version, mh-variant-p):
* lisp/mh-e/mh-comp.el (mh-insert-x-mailer):
Ensure mh-variant-in-use is set.

The fix will appear in Emacs 27.1.