// vcsGit describes how to use Git.
var vcsGit = &vcsCmd{
    name: "Git",
    cmd:  "git",

    createCmd:   []string{"clone --progress {repo} {dir}", "--git-dir={dir}/.git submodule update --init --recursive"},
    downloadCmd: []string{"pull --ff-only", "submodule update --init --recursive"},
    ...
}

// run1 is the generalized implementation of run and runOutput.
func (v *vcsCmd) run1(dir string, cmdline string, keyval []string, verbose bool) ([]byte, error) {
    ...
    var buf bytes.Buffer
    cmd.Stdout = &buf
    cmd.Stderr = &buf
    cmd.Stdout = os.Stdout // 新增
    cmd.Stderr = os.Stderr // 新增
    err = cmd.Run()
    out := buf.Bytes()
    ...
}