premount script fails with $RELEASE not defined

[Martin Pitt]

Current otto (r256) on saucy final.

$ sudo bin/otto create saucy-otto ~/download/ubuntu/saucy-desktop-amd64.iso

"sudo bin/otto start" fails without a meaningful error message. Running lxc-start directly shows the reason:

$ sudo lxc-start -n saucy-otto
[...]
+ APT_ARCHIVE=http://archive.ubuntu.com/ubuntu
/var/lib/lxc/saucy-otto/tools/scripts/pre-mount.sh: 105: /var/lib/lxc/saucy-otto/tools/scripts/pre-mount.sh: RELEASE: parameter not set
+ cat
lxc-start: Script exited with status 2
lxc-start: failed to run pre-mount hooks for container 'saucy-otto'.
lxc-start: failed to setup the container
lxc-start: invalid sequence number 1. expected 2
lxc-start: failed to spawn 'saucy-otto'
[...]

I worked around that by adding "export RELEASE=saucy" to /var/lib/lxc/saucy-otto/tools/scripts/pre-mount.sh