Restarting gnupg-agent inside X session

[Marco Steinacher]

Hi,

I use a OpenPGP smartcard with gnupg 2.0.14 and Ubuntu for different
tasks. From time to time I face the following problem: The gpg-agent
crashes for some reason after entering the PIN, 'ps' reports the daemon
process as a zombie

STAT START   TIME COMMAND
Zs   Feb26   0:01 [gpg-agent] <defunct>

and 'gpgconf --reload scdaemon' gives the following error:

gpgconf: error running `/usr/bin/gpg-connect-agent': exit status 1
gpgconf: error running `/usr/bin/gpg-connect-agent scd killscd': General
error

One problem is the fact that the agent crashes but I'm more after a
solution how to recover after it crashed for any reason. I can restart
the gpg-agent inside a terminal but then it is not available for
applications such as Thunderbird with Enigmail. So far, the only
solution that I know of is restarting the X session, i.e. log out and
log in again. But to do this I have to close all running applications
which sometimes is not an option.

Therefore I wonder if anybody knows of a solution to restart gpg-agent
on the level of the gnome-session without restarting the session itself.
Perhaps one way would be to somehow change the GPG_AGENT_INFO
environment variable for the running session, but I don't know if that's
possible. Any ideas?

Many thanks,
Marco