https://docs.nginx.com/nginx/admin-guide/load-balancer/tcp-udp-load-balancer/ see "prerequisites" per the ebuild for nginx-1.19.1 in order to enable --with-stream build option you have to enable one of the NGINX_MODULES_STREAM flags, otherwise there is no way to simply turn on that build option. nginx can handle streams without needing any of the other modules enabled. I got around this by enabling nginx_modules_stream_ssl_preread in package.use. the use case is to merely forward all traffic on a port to another port, even if the traffic is using SSL - bypassing the need to have SSL cert on the machine running nginx (no ssl termination); this is useful if you have a box hosting many domains/subdomains and want to reverse proxy to another host that, for instance, does not have a public IP. without --with-stream build option, you cannot use the "stream { }" directive in the nginx config files Suggestion then, is to have simply "stream" or "streams" as a use flag. Thank you!