OpenSSH_6.7p1 Debian-5+deb8u2 unix socket forwarding: Warning: remote port forwarding failed for listen path /home/sithglan/.gnupg/S.gpg-agent

[Thomas Glanzmann]

Hello,
I would like to forward my gpg-agent from a local workstation using a
remote machine:

(x1) [~] ssh -o "StreamLocalBindUnlink=yes" -R /home/sithglan/.gnupg/S.gpg-agent:/home/sithglan/.gnupg/S.gpg-agent remote.machine.de

when I do the same, I get the following error message:

Warning: remote port forwarding failed for listen path /home/sithglan/.gnupg/S.gpg-agent

>From my understanding StreamLocalBindUnlink=yes should delete the remote
listining socket before forwarding it. On the web other user report that
it is broken and someone should use a ~/.ssh/rc file to fight the
symptoms. My question is: Should it work like the above? Am I doing
something wrong? Is it fixed in a newer version and should I upgrade?

I'm using Debian Jessie 64 Bit, but fine with updating or patching sshd
to enable above usecase. Otherwise I'll go with the ~/.ssh/rc file.

Cheers,
        Thomas