$ git clone -n https://src.fedoraproject.org/rpms/gnome-nibbles.git /var/lib/mock/f40-build-791155-137124/root/chroot_tmpdir/scmroot/gnome-nibbles
Cloning into '/var/lib/mock/f40-build-791155-137124/root/chroot_tmpdir/scmroot/gnome-nibbles'...
$ git fetch origin a72943eddc0e64b13613e43f1648cf4a7fd3b04f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnome-nibbles
 * [new ref]         a72943eddc0e64b13613e43f1648cf4a7fd3b04f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a72943e Update to 4.0.2