$ git clone -n https://src.fedoraproject.org/rpms/expat.git /var/lib/mock/f45-build-42152-791/root/chroot_tmpdir/scmroot/expat
Cloning into '/var/lib/mock/f45-build-42152-791/root/chroot_tmpdir/scmroot/expat'...
$ git fetch origin e2141c82bd93935161c1fff296598537dc053a3c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/expat
 * [new ref]         e2141c82bd93935161c1fff296598537dc053a3c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e2141c8 Rebase to 2.8.3