bug#47159: 28.0.50; gnutls not recognized in build process without pkg-config

[Eli Zaretskii]

> Date: Thu, 18 Mar 2021 13:59:13 +0300
> From: Jean Louis <bugs@gnu.support>
> Cc: 47159@debbugs.gnu.org
> 
> * Lars Ingebrigtsen <larsi@gnus.org> [2021-03-18 08:52]:
> > So I guess we should just add a check for pkg-config in the gnutls
> > check?  Any opinions?
> 
> My opinion as a non-expert in the subject of preparation of
> `configure' script is that it should check for any fundamental command
> required for building.

I agree, and we do.

> Developers may forget those very basic packages/software as they
> rarely develop from a plain system.

Please don't generalize what is basically a simple oversight to imply
that Emacs developers are incompetent: the test for pkg-config is
there, we just don't announce its failure to the user.