$ git clone -n https://src.fedoraproject.org/rpms/gnome-nibbles.git /var/lib/mock/f41-build-836192-158789/root/chroot_tmpdir/scmroot/gnome-nibbles
Cloning into '/var/lib/mock/f41-build-836192-158789/root/chroot_tmpdir/scmroot/gnome-nibbles'...
$ git fetch origin 4853685bfc078ae3abd763922cd0e9a5c482836a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnome-nibbles
 * [new ref]         4853685bfc078ae3abd763922cd0e9a5c482836a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4853685 Update to 4.1.rc1