I had the same problem and managed to find a workaround :
Instead of typing : bzr break-lock lp-45673808:///~bertrand-goareguer/ufw/ufw-qos/.bzr/branch/lock
I typed : bzr break-lock bzr+ssh://<email address hidden>/~bertrand-goareguer/ufw/ufw-qos/.bzr/branch/lock
Then I simply answered 'yes' to the question asked by bzr.
I had the same problem and managed to find a workaround : ///~bertrand- goareguer/ ufw/ufw- qos/.bzr/ branch/ lock /~bertrand- goareguer/ ufw/ufw- qos/.bzr/ branch/ lock
Instead of typing : bzr break-lock lp-45673808:
I typed : bzr break-lock bzr+ssh://<email address hidden>
Then I simply answered 'yes' to the question asked by bzr.