is to a redis server

when 127.0.0.1 went further

i've seen in other code when localhost, was different then with 127.0.0.1

Try ulimit -n 30000, then in the same shell:
v -d net_blocking_sockets run redis_connect_error.v

on osx m.1

I don't have an m1 mac so i cant test this necessarily. From the error message it

1. successfully resolves the address to something(s).

  addrs := resolve_addrs_fuzzy(address, .tcp) or {
  	return error('$err.msg(); could not resolve address $address in dial_tcp')
  }

2. Goes through those addresses, creating sockets, trying to connect and failing to connect (for whatever reason, we could do with a better way of passing the why down to the end user).

  for addr in addrs {
  	mut s := new_tcp_socket(addr.family()) or {
  		return error('$err.msg(); could not create new tcp socket in dial_tcp')
  	}
  	s.connect(addr) or {
  		// Connection failed
  		s.close() or { continue }
  		continue
  	}

4. Returns an error because none of the sockets it created pointing to those addresses successfully connected.

   }
   // failed
   return error('dial_tcp failed for address $address')

I think i mentioned to @medvednikov one time that it could be alignment related (given m1 is arm and not x64), however I have never been able to test this. All I know is that there is no issue with this on windows, or linux on x64

If you add a socket.close() at the end then this goes away.

module main

import net

fn do()?{
        for i in 0 .. 10000{
                println(i)
                mut socket := net.dial_tcp("localhost:6379")?
                println("Connected successfully")
                socket.close()?
        }
}

fn main() {
        do() or { panic(err) }
}

Could I recommend closing your sockets after you have finished using them (atleast if they are still open)? My other thoughts are that it might be trying to re-use a local port for the same socket that is still open (because you havent closed it. No idea how to check that though...)