Sure. Send a change. I'd hope the change has docs referencing any specs, and tests?

I'll definitely keep it in mind for any patch. I have to admit my understanding of what supporting socks5h:// would entail was more cursory when first filing this issue (now realize it will be more complicated), but I'm willing to take a look.

Here is what curl does if socks5h is set

https://github.com/bagder/curl/blob/master/lib/socks.c#L569-L573

Just glancing at net/proxy/socks5.go in Dial()

        if ip := net.ParseIP(host); ip != nil {
                if ip4 := ip.To4(); ip4 != nil {
                        buf = append(buf, socks5IP4)
                        ip = ip4
                } else {
                        buf = append(buf, socks5IP6)
                }
                buf = append(buf, ip...)
        } else {
                if len(host) > 255 {
                        return nil, errors.New("proxy: destination hostname too long: " + host)
                }
                buf = append(buf, socks5Domain)
                buf = append(buf, byte(len(host)))
                buf = append(buf, host...)
        }

Looks like socks5 is already acting like socks5h?

@dajohi If that's the case, it might just need to be updated to support socks5h:// notation, and maybe to skip the hostname checking in the case of simply socks5://. I can't find any official RFC describing socks5h:// notation specifically though.

Bumping this, since it's we've seen it cause some failures in docker/docker-machine (17.05).

Change https://golang.org/cl/156517 mentions this issue: proxy: support socks5h scheme in proxy URL