$ git clone -n https://src.fedoraproject.org/rpms/ignition.git /var/lib/mock/f42-build-3426598-45197/root/chroot_tmpdir/scmroot/ignition
Cloning into '/var/lib/mock/f42-build-3426598-45197/root/chroot_tmpdir/scmroot/ignition'...
$ git fetch origin a13fc832991d52be743f12e16fc5af5652256720:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ignition
 * [new ref]         a13fc832991d52be743f12e16fc5af5652256720 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a13fc83 Update to 2.21.0