$ git clone -n https://src.fedoraproject.org/rpms/jackson-databind.git /var/lib/mock/f40-build-2423492-60593/root/chroot_tmpdir/scmroot/jackson-databind
Cloning into '/var/lib/mock/f40-build-2423492-60593/root/chroot_tmpdir/scmroot/jackson-databind'...
$ git fetch origin 4f9e39a342517fb22ee5fefede4b33fab79d15e6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/jackson-databind
 * [new ref]         4f9e39a342517fb22ee5fefede4b33fab79d15e6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4f9e39a Conditionalize arches for RHEL