crypto/x509: COMODO certifification got x509: certificate signed by unknown authority

[SunRunAway]

What version of Go are you using (go version)?

go1.4.2

What operating system and processor architecture are you using?

darwin/amd64

What did you do?

run this program,

package main

import (
    "fmt"
    "net/http"
)

func main() {
    url := "https://catchchat.catchchatchina.com/"
    _, err := http.Head(url)
    if err != nil {
        fmt.Println(err)
    }
}

What did you expect to see?

do not print the error. This url can be opened in browsers.

What did you see instead?

[sunrunaway:~/Code/go/bin]$ go run ~/Code/gotmp/httpget.go                                                    (master) 
Head https://catchchat.catchchatchina.com/: x509: certificate signed by unknown authority

[linniksa]

To fix this problem, you must add certificates of "COMODO RSA Domain Validation Secure Server CA" to your certififcate served from server, also see full report at https://www.ssllabs.com/ssltest/analyze.html?d=catchchat.catchchatchina.com

[SunRunAway]

@linniksa Thanks.