$ git clone -n https://src.fedoraproject.org/rpms/g3kb-switch.git /var/lib/mock/f40-build-2245286-53757/root/chroot_tmpdir/scmroot/g3kb-switch
Cloning into '/var/lib/mock/f40-build-2245286-53757/root/chroot_tmpdir/scmroot/g3kb-switch'...
$ git fetch origin dc36f972e3e76087654eec9d000250d7c9240da7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/g3kb-switch
 * [new ref]         dc36f972e3e76087654eec9d000250d7c9240da7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at dc36f97 Workaround for incorrect version reporting