$ git clone -n https://src.fedoraproject.org/rpms/xrootd.git /var/lib/mock/f40-build-735150-106208/root/chroot_tmpdir/scmroot/xrootd
Cloning into '/var/lib/mock/f40-build-735150-106208/root/chroot_tmpdir/scmroot/xrootd'...
$ git fetch origin 534722bfd519fd48f8d0592d06978791e31b3073:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/xrootd
 * [new ref]         534722bfd519fd48f8d0592d06978791e31b3073 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 534722b Update to version 5.6.3