vc-switch-backend

vc-switch-backend is an interactive autoloaded compiled Lisp function in `vc.el'.

It is bound to C-x v b.

(vc-switch-backend FILE BACKEND)

Make BACKEND the current version control system for FILE.
FILE must already be registered in BACKEND. The change is not
permanent, only for the current session. This function only changes
VC's perspective on FILE, it does not register or unregister it.
By default, this command cycles through the registered backends.
To get a prompt, use a prefix argument.