KOHA_ELASTICSEARCH=1 has no effect

Reproduice

Are the following usages correct?

export KOHA_ELASTICSEARCH=1 KOHA_IMAGE=master-buster ; ku-md10

It's the same, but with ku and using the expanded version , because there was suspicions that the alias could somehow be interfering with the exports.

export KOHA_ELASTICSEARCH=1 ; cd "${KOHA_TESTING_DOCKER_HOME}"; docker-compose -f docker-compose.yml -p koha up --force-recreate

What happens

The issue the syspref is still to Zebra and ES isn't indexed.

Logs

koha_1       | Running [PERL5LIB=/kohadevbox/koha:/kohadevbox/qa-test-tools perl /kohadevbox/misc4dev/reset_plack.pl --koha_dir=/kohadevbox/koha --instance=kohadev]...
koha_1       | Running [sudo service apache2 restart]...
es_1         | [2020-06-03T22:52:01,705][INFO ][o.e.c.r.a.DiskThresholdMonitor] [hfDb8zv] low disk watermark [85%] exceeded on [hfDb8zvdSn-DmHBzVheslQ][hfDb8zv][/usr/share/elasticsearch/data/nodes/0] free: 55.6gb[12.1%], replicas will not be assigned to this node
koha_1       | Restarting Apache httpd web server: apache2.
koha_1       | Running [koha-mysql kohadev -e 'UPDATE systempreferences SET value="Zebra" WHERE variable="SearchEngine"']...
koha_1       | Running [sudo koha-rebuild-zebra -f -v kohadev]...