gohugoio/hugo · error

--appendPort=false not supported when in multihost mode

Error message

--appendPort=false not supported when in multihost mode

What it means

In multihost mode (each language served on its own host), Hugo must run one listener per language, allocating sequential ports and appending each port to that language's baseURL. `--appendPort=false` would make the per-language servers indistinguishable on one origin, so `createServerPorts` rejects the combination outright.

Source

Thrown at commands/server.go:761

		Roots:   roots,
	}

	if _, err := cert.Verify(opts); err != nil {
		return fmt.Errorf("failed to verify certificate: %v", err.Error())
	}

	return nil
}

func (c *serverCommand) createServerPorts(cd *simplecobra.Commandeer) error {
	flags := cd.CobraCommand.Flags()
	var cerr error
	c.withConf(func(conf *commonConfig) {
		isMultihost := conf.configs.IsMultihost
		c.serverPorts = make([]serverPortListener, 1)
		if isMultihost {
			if !c.serverAppend {
				cerr = errors.New("--appendPort=false not supported when in multihost mode")
				return
			}
			c.serverPorts = make([]serverPortListener, len(conf.configs.Languages))
		}
		currentServerPort := c.serverPort
		for i := range c.serverPorts {
			l, err := net.Listen("tcp", net.JoinHostPort(c.serverInterface, strconv.Itoa(currentServerPort)))
			if err == nil {
				c.serverPorts[i] = serverPortListener{ln: l, p: currentServerPort}
			} else {
				if i == 0 && flags.Changed("port") {
					// port set explicitly by user -- he/she probably meant it!
					cerr = fmt.Errorf("server startup failed: %s", err)
					return
				}
				c.r.Println("port", currentServerPort, "already in use, attempting to use an available port")
				l, sp, err := helpers.TCPListen()
				if err != nil {

View on GitHub ↗ (pinned to 8a468df065)

Solutions

1. Remove `--appendPort=false` and let Hugo append a distinct port per language (ports increment from `--port`).
2. If you need portless URLs, front the per-language ports with a reverse proxy instead of disabling appendPort.
3. If multihost isn't intended, remove the per-language `baseURL` overrides so the site is single-host, then `--appendPort=false` works.

Example fix

# before
hugo server --appendPort=false   # multilingual site with per-language baseURLs
# after
hugo server                      # each language gets its own port

if multihost && !flags.AppendPort {
    return errors.New("multihost mode requires appendPort=true; remove --appendPort=false")
}

When it happens

Trigger: Running `hugo server --appendPort=false` on a site where `conf.configs.IsMultihost` is true — i.e. a multilingual config where languages define different `baseURL` values.

Common situations: Multilingual sites that set per-language baseURLs (which silently enables multihost) combined with a habit of `--appendPort=false` to get clean URLs; reverse-proxy dev setups that want portless URLs; copying server flags from a single-host project.

Related errors

• multihost change detected, please restart server
• cannot use --renderToMemory with --destination
• failed to create baseURL from %q: %s
• failed to parse root certificate
• failed to parse certificate PEM

AI-assisted analysis of gohugoio/hugo@8a468df065 (2026-07-31). Data as JSON: /data/errors/547a11c8df0445dc.json. Report an issue: GitHub ↗.