lua_socket_log_errors does not suppress errors connecting to unix-domain sockets

If using the lua_socket_log_errors off setting, this option seems to have no effect on connection errors to unix-domain sockets. Connection errors to unix domain sockets seem to be logged to the error log regardless of this setting. Compare that to connecting to a host and port, in which case the lua_socket_log_errors off setting successfully suppresses from the error from the nginx error log.

I'm currently testing this against OpenResty 1.15.8.2.

Here's an example:

worker_processes 1;
error_log logs/error.log;
events {
  worker_connections 1024;
}
http {
  lua_socket_log_errors off;
  server {
    listen 8080;
    location / {
      content_by_lua_block {
        local sock = ngx.socket.tcp()
        sock:connect("unix:/tmp")
      }
    }
  }
}

Which generates this line in the error log:

2019/11/01 15:14:33 [error] 355#355: *1 connect() to unix:/tmp failed (111: Connection refused), client: 127.0.0.1, server: , request: "GET / HTTP/1.1", host: "localhost:8080"

Compare that to when connecting to host/ports, like sock:connect("127.0.0.1", 9999) (or some other port that isn't running locally), which does not log any connection refused errors as long as lua_socket_log_errors off is set (but does log connection refused errors when lua_socket_log_errors on).

Is it possible for lua_socket_log_errors to also toggle error logging behavior for unix-domain sockets? Thanks!

Start by reproducing the provided nginx configuration and compare the unix-domain socket case with the TCP connection case under lua_socket_log_errors off and on. Trace where connection errors are logged for each path. Done means unix-domain socket errors are suppressed when the setting is off and remain logged when it is on.