As I can see this is related to https://bugs.launchpad.net/bugs/760435
Vincent made backport of deprecation changes from bzr trunk and therefore some functions from bzr 2.4 now moans about incompatibility with bzr 2.4.
I don't know if it's intended or just result of not very well backport. Anyway I don't think it worth to spend a time on it.
As I can see this is related to https:/ /bugs.launchpad .net/bugs/ 760435
Vincent made backport of deprecation changes from bzr trunk and
therefore some functions from bzr 2.4 now moans about incompatibility
with bzr 2.4.
I don't know if it's intended or just result of not very well backport.
Anyway I don't think it worth to spend a time on it.