"Bence Ferdinandy" [off-list ref] writes:

Good point, and yes, that is what happens. (Although I'm not quite sure how
valid that state is where a remote's HEAD is not a branch).

Not often when you cloned from a publishing repository, but if you
cloned from a repository for your own work with an worktree, the
HEAD at such an origin repository may have been detached, so it
would be sensible (I think "git clone" historically guesses over
eagerly to hide the detached HEAD state of the other side, though)
if the clone's remote-tracking HEAD reflects it, I would think.

... So maybe if we put "Not a symbolic reference." in the referent
(which should be an invalid symref), the caller could check for that and then
should be able to distinguish this special case?

Yuck.

Are we limited by the narrow interface that only passes "referent",
or are you in the position that allows you to extend the interface
to "do it right"?