$ git clone -n https://src.fedoraproject.org/rpms/xu4.git /var/lib/mock/f40-build-2626571-65284/root/chroot_tmpdir/scmroot/xu4
Cloning into '/var/lib/mock/f40-build-2626571-65284/root/chroot_tmpdir/scmroot/xu4'...
$ git fetch origin 5f930e7f8319b502312ea126afb9bea805caa37c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/xu4
 * [new ref]         5f930e7f8319b502312ea126afb9bea805caa37c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5f930e7 Convert to %autorelease and %autochangelog