Comment 2 for bug 1771011

Confirmed this in a Cosmic container this morning. It appears the version in cosmic has an issue with the underscore.

Steps to reproduce:
1. lxc launch ubuntu-daily:c c
2. lxc exec c bash
3. echo "PermitUserEnvironment yes" > /etc/ssh/sshd_config
4. ssh-import-id <your id>
5. add environment="FOO_BAR=1" to start of ssh key line ~/.ssh/authorized_keys
6. attempt to ssh to container and get Permission denined
7. remove the underscore, attempt to ssh again, and ssh will be sucessful