junegunn/fzf · error

socket already in use: %s

Error message

socket already in use: %s

What it means

Error "socket already in use: %s" thrown in junegunn/fzf.

Source

Thrown at src/server.go:96

	return listenAddress{parts[0], port, ""}, nil
}

func startHttpServer(address listenAddress, actionChannel chan []*action, getHandler func(getParams) string) (net.Listener, int, error) {
	host := address.host
	port := address.port
	apiKey := os.Getenv("FZF_API_KEY")
	if !address.IsLocal() && len(apiKey) == 0 {
		return nil, port, errors.New("FZF_API_KEY is required to allow remote access")
	}

	var listener net.Listener
	var err error
	if len(address.sock) > 0 {
		if _, err := os.Stat(address.sock); err == nil {
			// Check if the socket is already in use
			if conn, err := net.Dial("unix", address.sock); err == nil {
				conn.Close()
				return nil, 0, fmt.Errorf("socket already in use: %s", address.sock)
			}
			os.Remove(address.sock)
		}
		listener, err = net.Listen("unix", address.sock)
		if err != nil {
			return nil, 0, fmt.Errorf("failed to listen on %s", address.sock)
		}
		os.Chmod(address.sock, 0600)
	} else {
		addrStr := fmt.Sprintf("%s:%d", host, port)
		listener, err = net.Listen("tcp", addrStr)
		if err != nil {
			return nil, port, fmt.Errorf("failed to listen on %s", addrStr)
		}
		if port == 0 {
			addr := listener.Addr().String()
			parts := strings.Split(addr, ":")
			if len(parts) < 2 {

View on GitHub (pinned to bd4efa277b)

Solutions

1. Remove the stale socket file and retry: rm <socket-path>
2. Stop the process currently bound to the socket, then retry
3. Point --listen at a different socket path or TCP port

When it happens

Trigger: Thrown at src/server.go:96 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of junegunn/fzf@bd4efa277b (2026-08-15). Data as JSON: /api/errors/ab459fa3af73f9dd. Report an issue: GitHub.