$ git clone -n https://src.fedoraproject.org/rpms/jackson-modules-base.git /var/lib/mock/f40-build-2410379-60560/root/chroot_tmpdir/scmroot/jackson-modules-base
Cloning into '/var/lib/mock/f40-build-2410379-60560/root/chroot_tmpdir/scmroot/jackson-modules-base'...
$ git fetch origin 98de7138c9a2fce86873907802b6daf595177c27:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/jackson-modules-base
 * [new ref]         98de7138c9a2fce86873907802b6daf595177c27 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 98de713 Conditionalize arches for RHEL