I'm trying to change the key bindings to all the smerge commands. I added :
(setq smerge-command-prefix "\C-c v") to my Emacs config. M-x customize smerge confirms that the Smerge Command Prefix is ^C v but all my smerge commands still starts with C-c ^.
I also tried
(setq smerge-command-prefix (kbd "C-c v")) but same result.
It looks like this will take effect if you restart Emacs.
Alternatively, M-x load-library RET smerge RET will process it. (In which case the old prefix will also remain active, until you restart.)
load-library also but still nothing. Thanks though. (setq smerge-command-prefix (kbd "C-c v")) in Emacs 26.1. emacs -Q and it works perfectly. After spending some time investigating the problem in my emacs config, I found the source of the problem to be magit-filenotify.el (github.com/ruediger/magit-filenotify). I'm not sure yet why it breaks this keybinding. smerge-command-prefix is used by smerge.el when the smerge.el file is loaded. So you need to perform your setq before smerge.el is loaded. My crystal ball tells me that you likely have something in your .emacs which causes smerge to be loaded before that setq.
magit-filenotify.el solves the issue (As explain to @phils) but smerge.el isn't called by this file. I still have to take the time to understand why. magit which requires magit-diff which requires smerge-mode
M-x customize smergepointed me to the answer:M-x customize-variable RET smerge-command-prefix.