When using the ssh:ssh command, the current ssh client calls KarafAgentFactory which expects the SSH_AUTH_SOCK env variable to be set, so work around the problem by registering the CommandSession in osgi so that this variable is correctly initialised.
Force the use of scr 1.6.2 (at the cost of loosing the scr commands for now)
Try to remove exceptions caused by groups trying to close cleanly while curator is unregistered (not sure it really works though).