Question about changes to configure.ac/configure scripts.

[Etan Reisner]

While looking into other configure.ac changes I noticed that the
PKG_CHECK_MODULES macro we currently use to handle finding the correct
include and lib directories for many of our dependencies already support
manual override of their automatic results through the use of *_CFLAGS and
*_LIBS environment variables.

I also noticed that for certain dependencies (such as Avahi, SILC,
Gadu-Gadu, and the SSL libraries) we also support overriding pkg-config
via --with-*-includes and --with-*-libs configure flags. This seems
redundant and confusing to me (not to mention causes our configure.ac file
to be significantly more complex than it needs to be).

I'd like to remove the --with-*-* flags if possible. So the question is do
any of the packagers currently use the --with-*-* configure flags (to
override pkg-config) and if you do would switching to using the
environment variables be overly problematic?

Anyone have and other reasons why we wouldn't want to remove those flags?
(We can't remove all of them as a small number of our older/more-exotic
dependencies don't appear to use pkg-config yet.)

    -Etan

P.S. I will probably, unless people think this isn't worth it, attempt to
hook the removed flags up to a dummy snippet which errors with a message
explaining the change. Oh, and since someone in the
devel at conference.pidgin.im asked when I brought this up there the various
env vars are listed at the end of the './configure --help' output.