For 2.3:

The gnupg daemons have a feature to redirect sockets using a plain file instead
of a socket file. Although supported by libassuan and sharing some code with
the Windows socket emulation, it is quite complex. With the move to /var/run by
default for sockets, there is actually no need for this anymore.

As a bonus we could try to implement Justus' idea on how to use relative socket
files.