$ git clone -n https://src.fedoraproject.org/rpms/libmacaroons.git /var/lib/mock/f40-build-2210982-52193/root/chroot_tmpdir/scmroot/libmacaroons
Cloning into '/var/lib/mock/f40-build-2210982-52193/root/chroot_tmpdir/scmroot/libmacaroons'...
$ git fetch origin d07838b58ae9383744afdb608a94c48c2dce3a70:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libmacaroons
 * [new ref]         d07838b58ae9383744afdb608a94c48c2dce3a70 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d07838b rebuild for new libsodium