Comment 28 for bug 366728

All of the work-arounds that have been listed everywhere up until this point have required root to change something in /etc/X11. Further, I don't particularly want to disable ssh-agent from loading.

Assuming Ubuntu uses a similar xsession configuration to Debian Jessie (which I imagine would be a safe bet), here is an alternative solution that can work - no root access required:

Just create a .xsession file with the contents:

#!/bin/bash

export $LD_LIBRARY_PATH=...whatever...

# Start our session manager of choice.
exec x-session-manager
### end

Make .xsession executable, and you should be in business. Read /etc/X11/Xsession.d/50x11-common_determine-startup, 90x11-common_ssh-agent and 99x11-common_start for a clear picture of why this works.

Requires allow-user-xsession to be set in /etc/X11/Xsession.options, but this is the default.