If there's a git remote named "foo", and a special remote with the same name, git annex enableremote foo just prints "ok" and silently does nothing.

Perhaps worse, passing enableremote the uuid of the special remote causes it to modify the same named git remote's config, adding/replacing annex-uuid and adding whatever other git configs the special remote uses. --Joey

(initremote does check if there's already a remote with the same name, and refuses to overwrite it).