gnome-session fails over SSH to remote PC

Using Ubuntu 17.10 Desktop 64 bit I am unable to start a gnome-session on my local Ubuntu 17.04 Desktop inside a Xephyr server over SSH. This is probably the same bug as https://bugs.launchpad.net/ubuntu/+source/gnome-session/+bug/1251281 but I don't see a fix for 17.10 and could not add 17.10 to that bug report. When I try, I get: https://bugs.launchpad.net/ubuntu/+source/gnome-session/+bug/1251281/+distrotask

Setup:

local PC is 64 bit Ubuntu Desktop 17.04 - fully updated
remote PC is 64 bit Ubuntu Desktop 17.10 - fully updated

start Xephyr on local PC using:

~$ Xephyr :2 -screen 1280x900 &

set up DISPLAY

~$ export DISPLAY=:2

ssh to remote PC

~$ ssh -YC user@remote

now logged into remote - do a simple test:

~$ xeyes

I see the xeyes open on my local desktop inside the Xephyr window success. Press CTRL-C in terminal to exit xeyes.

Try to start gnome-session on remote with:

~$ gnome-session --debug

I get the following on the console:

gnome-session-binary[17018]: DEBUG(+): Enabling debugging
gnome-session-binary[17018]: DEBUG(+): hardware acceleration check failed: Child process exited with code 1
gnome-session-binary[17018]: WARNING: software acceleration check failed: Child process exited with code 1
gnome-session-binary[17018]: CRITICAL: We failed, but the fail whale is dead. Sorry....

I expected a non-accelerated gnome session to start inside the Xephyr window. It does not.