$ git clone -n https://src.fedoraproject.org/rpms/FlightGear.git /var/lib/mock/f38-build-side-42-init-devel-603420-26218/root/chroot_tmpdir/scmroot/FlightGear
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-603420-26218/root/chroot_tmpdir/scmroot/FlightGear'...
$ git fetch origin be181e27316e3974e1999f34eff68797bc36158b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/FlightGear
 * [new ref]         be181e27316e3974e1999f34eff68797bc36158b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at be181e2 new upstream release