txthinking/brook · error

Looks like you want create socks5 from a socks5, you may wan

Error message

Looks like you want create socks5 from a socks5, you may want $ brook socks5tohttp?

What it means

The socks5 subcommand is meant to wrap a non-socks5 upstream (a brook link, ss link, etc.) and expose it as a local socks5 server. brook.ParseLink returns kind == "socks5" for a socks5:// link, and since wrapping socks5-in-socks5 is meaningless (and socks5tohttp exists for the reverse direction), main.go:493 rejects it with this guidance error.

Source

Thrown at cli/brook/main.go:493

				}
				if c.String("socks5ServerIP") != "" {
					h = c.String("socks5ServerIP")
				}
				if h == "" {
					return errors.New("socks5 server requires a clear IP for UDP, only port is not enough. You may use loopback IP or lan IP or other, we can not decide for you")
				}
				kind, _, v, err := brook.ParseLink(link)
				if err != nil {
					return err
				}
				if s := v.Get("clientHKDFInfo"); s != "" {
					brook.ClientHKDFInfo = []byte(s)
				}
				if s := v.Get("serverHKDFInfo"); s != "" {
					brook.ServerHKDFInfo = []byte(s)
				}
				if kind == "socks5" {
					return errors.New("Looks like you want create socks5 from a socks5, you may want $ brook socks5tohttp?")
				}
				s, err := brook.NewBrookLink(link)
				if err != nil {
					return err
				}
				err = s.PrepareSocks5Server(c.String("socks5"), h, c.Int("tcpTimeout"), c.Int("udpTimeout"))
				if err != nil {
					return err
				}
				g.Add(&runnergroup.Runner{
					Start: func() error {
						return s.ListenAndServe()
					},
					Stop: func() error {
						return s.Shutdown()
					},
				})
				if c.String("http") != "" {

View on GitHub (pinned to 5cd13ef3b1)

Solutions

1. If the goal is a local socks5 for an existing socks5 server, just use the socks5 server directly — no wrapping needed
2. If you wanted HTTP from socks5, run `brook socks5tohttp --from socks5://...` as the message suggests
3. Use a non-socks5 link (brook:// or ss://) as the --from value for this subcommand

Example fix

// before
brook socks5 --from socks5://user:pass@1.2.3.4:1080
// after
brook socks5tohttp --from socks5://user:pass@1.2.3.4:1080
// or, for a brook upstream:
brook socks5 --from brook://1.2.3.4:9999

case "${from%%://*}" in
  socks5) echo "upstream is already socks5; use it directly or run brook socks5tohttp" >&2; exit 1 ;;
esac

When it happens

Trigger: Running `brook socks5 --from socks5://user:pass@host:1080 ...` — i.e. passing a link whose parsed scheme/kind is "socks5" into the socks5 subcommand.

Common situations: Users who already have a socks5 server and want a local proxy copy-paste it as the upstream link; automation pipelines that generically feed proxy URIs without checking the scheme; confusion between the socks5 (server wrapper) and socks5tohttp subcommands.

Understand the failure class

Background: "is not a compatible type" / "cannot merge" errors: when a value's type doesn't match what the library requires — this error's family across 65 libraries.

Related errors

• socks5 server requires a clear IP for UDP, only port is not
• --cert must be with absolute path
• --certkey must be with absolute path
• socks5 server requires a clear IP for UDP, only port is not
• cannot create exchanger from

AI-assisted analysis of txthinking/brook@5cd13ef3b1 (2026-09-06). Data as JSON: /api/errors/3642940f637fa2ce. Report an issue: GitHub.