$ git clone -n https://src.fedoraproject.org/rpms/h3.git /var/lib/mock/f42-build-side-1-3582412-46884/root/chroot_tmpdir/scmroot/h3
Cloning into '/var/lib/mock/f42-build-side-1-3582412-46884/root/chroot_tmpdir/scmroot/h3'...
$ git fetch origin 2ff32d306a3c574104c9f8d2220f14fedb33d82c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/h3
 * [new ref]         2ff32d306a3c574104c9f8d2220f14fedb33d82c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2ff32d3 4.3.0