Cannot connect kdb+ through unix domain socket

Here is my code, please check it out.
package main

import (
    "bytes"
    "fmt"
    "log"
    "os"
    "os/exec"
    "strconv"

    kdb "github.com/sv/kdbgo"
)

var testPort = 0

func StartQ(ready chan struct{}) {
    fmt.Println("Starting q process on random port")
    _, err := exec.LookPath("q")
    if err != nil {
        log.Fatal("installing q is in your future")
    }
    cmd := exec.Command("q", "-p", "0W", "-q")
    stdin, err := cmd.StdinPipe()
    if err != nil {
        log.Fatal("Failed to connect stdin", err)
    }
    stdin.Write([]byte(".z.pi:.z.pg:.z.ps:{value 0N!x};system\"p\"\n"))
    stdout, err := cmd.StdoutPipe()
    if err != nil {
        log.Fatal("Failed to connect stdout", err)
    }
    stderr, err := cmd.StderrPipe()
    if err != nil {
        log.Fatal("Failed to connect stderr", err)
    }
    err = cmd.Start()
    if err != nil {
        log.Fatal("Failed to start q", err)
    }
    buf := make([]byte, 16)
    n, err := stdout.Read(buf)
    if err != nil {
        log.Fatal("Failed to fill port number for child process: ", err)
    }
    testPort, err = strconv.Atoi(string(buf[:bytes.IndexByte(buf, 'i')]))
    if err != nil {
        fmt.Println("Failed to setup listening port", string(buf[:n]), err)
        cmd.Process.Kill()
        os.Exit(1)
    }
    fmt.Println("Listening port is ", testPort)
    go func() {
        for {
            buf := make([]byte, 256)
            n, err := stderr.Read(buf)
            fmt.Println("Q stderr output:", string(buf[:n]))
            if err != nil {
                fmt.Println("Q stderr error:", err)
                return
            }
        }
    }()
    go func() {
        for {
            buf := make([]byte, 256)
            _, err := stdout.Read(buf)
            //fmt.Println("Q stdout output:", string(buf[:n]))
            if err != nil {
                fmt.Println("Q stdout error:", err)
                return
            }
        }
    }()
    ready <- struct{}{}
    cmd.Wait()
    //stdin.Write([]byte("show `exiting_process;\nexit 0\n"))
}

func main() {
    ready := make(chan struct{})
    go StartQ(ready)

    <-ready
    log.Println("Connect to kdb+ through unix socket.")
    con, err := kdb.DialUnix("localhost", testPort, "")
    if err != nil {
        panic(err)
    }

    log.Println("Close the connection")
    err = con.Close()
    if err != nil {
        panic(err)
    }
}
sv / kdbgo

Cannot connect kdb+ through unix domain socket #23
