It appears that this is caused by #159 ++ erl -eval 'io:format("~p", [code:lib_dir(ssl, ebin)]),halt().' -noshell + export 'ERL_SSL_PATH="/usr/lib/erlang/lib/ssl-8.1.1/ebin"' + ERL_SSL_PATH='"/usr/lib/erlang/lib/ssl-8.1.1/ebin"' + sslErlArgs='-pa "/usr/lib/erlang/lib/ssl-8.1.1/ebin" -proto_dist inet_tls -ssl_dist_opt server_certfile /tmp/combined.pem -ssl_dist_opt server_secure_renegotiate true client_secure_renegotiate true' /docker-entrypoint.sh: line 401: RABBITMQ_SERVER_ADDITIONAL_ERL_ARGS: unbound variable