$ git clone -n https://src.fedoraproject.org/rpms/xreader.git /var/lib/mock/f40-build-2184579-51282/root/chroot_tmpdir/scmroot/xreader
Cloning into '/var/lib/mock/f40-build-2184579-51282/root/chroot_tmpdir/scmroot/xreader'...
$ git fetch origin b1f206b451cda4970bafca1fd58b84a5f7d47ca1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/xreader
 * [new ref]         b1f206b451cda4970bafca1fd58b84a5f7d47ca1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b1f206b Update to 4.0.1 release