$ git clone -n https://src.fedoraproject.org/rpms/xorg-x11-server.git /var/lib/mock/f42-build-side-1-3583846-46890/root/chroot_tmpdir/scmroot/xorg-x11-server
Cloning into '/var/lib/mock/f42-build-side-1-3583846-46890/root/chroot_tmpdir/scmroot/xorg-x11-server'...
$ git fetch origin 5d7ed4931eb5a7d2c3832549ad66d663f872e46d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/xorg-x11-server
 * [new ref]         5d7ed4931eb5a7d2c3832549ad66d663f872e46d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5d7ed49 Update to v21.1.18