Seahorse-agent and the "gpg-agent-info" option

["Philip Allison" <sane not co uk>]

I've been trying (not particularly hard, yet) to get seahorse-agent
integrated properly into my GNOME session, and noticed something
strange.  By default, seahorse-agent makes itself known to the gpg tools
by setting the "gpg-agent-info" option in ~/.gnupg/gpg.conf - all well
and good, except that GnuPG 2 doesn't honour this option any more.  This
is intentional; I've searched the GnuPG mailing lists, and they claim
the option was only really for use during development of gpg-agent.

Bearing this in mind, what's the easiest way to get seahorse started
with the environment variables exported session-wide?

Regards