$ git clone -n https://src.fedoraproject.org/rpms/hostname.git /var/lib/mock/f45-build-13476-451/root/chroot_tmpdir/scmroot/hostname
Cloning into '/var/lib/mock/f45-build-13476-451/root/chroot_tmpdir/scmroot/hostname'...
$ git fetch origin a9369dc40d37c8c0709f158267298e81e6156b8e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/hostname
 * [new ref]         a9369dc40d37c8c0709f158267298e81e6156b8e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a9369dc Add test plans from CentOS