$ git clone -n https://src.fedoraproject.org/rpms/jhead.git /var/lib/mock/f40-build-2210199-52178/root/chroot_tmpdir/scmroot/jhead
Cloning into '/var/lib/mock/f40-build-2210199-52178/root/chroot_tmpdir/scmroot/jhead'...
$ git fetch origin 045cdfea1c7ba8d5ca4c8b27b35ea0d130eac9d6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/jhead
 * [new ref]         045cdfea1c7ba8d5ca4c8b27b35ea0d130eac9d6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 045cdfe updated to 3.08