git shortlog -s -n -e --no-merges output [] in go test but the call in the main function is normal output

this is Author struct

type Author struct {
    Name         string
    Email        string
    CommitNumber int
}

// get all authors
func GetAllAuthor() []Author {
    args := []string{"shortlog", "-s", "-n", "-e", "--no-merges"}
    var authors []Author

    info := utils.MustExecRtOut(Cmd, args...)

    lines := strings.Split(info, "\n")
    for _, line := range lines {
        if len(strings.TrimSpace(line)) > 0 {
            author := GetAuthor(line)
            authors = append(authors, author)
        }
    }
    return authors
}

// get information about an author
func GetAuthor(line string) Author {
    authorInfo := strings.Fields(strings.TrimSpace(line))
    emailIndex := len(authorInfo) - 1

    email := strings.TrimSpace(authorInfo[emailIndex])
    email = utils.SubString(email, 1, len(email)-1)
    author := strings.Join(authorInfo[1:emailIndex], " ")
    number, err := strconv.Atoi(authorInfo[0])

    if err != nil {
        fmt.Printf("%s parse commit number %s error!\n", line, authorInfo[0])
    }

    return Author{
        Name:         author,
        Email:        email,
        CommitNumber: number,
    }

}

When I call GetAllAuthor in the test function, the output is an empty array [], but when I debug or call it in the main function, the output can be normal,like this [{Joeeeeeeey 123@xx.com 169} {Tony 123@xx.com 62}]