How to retrieve stdout when piping several commands in Go - docker

Question

I'm writing a Go function to upload local Docker images to an instance that has SSH access. I'm using the following method for this:
cmdSave := exec.Command("docker", "save", image)
cmdLoad := exec.Command("ssh", fmt.Sprintf("%s#%s", user, externalIP), "docker load")
read, write := io.Pipe()
cmdSave.Stdout = write
cmdLoad.Stdin = read
var buffer bytes.Buffer
cmdLoad.Stdout = &buffer
var stderrSave bytes.Buffer
cmdSave.Stderr = &stderrSave
var stderrLoad bytes.Buffer
cmdLoad.Stderr = &stderrLoad
err = cmdSave.Start()
if err != nil {
return errors.Wrap(err, stderrSave.String())
}
err = cmdLoad.Start()
if err != nil {
return errors.Wrap(err, stderrLoad.String())
}
err = cmdSave.Wait()
if err != nil {
return errors.Wrap(err, stderrSave.String())
}
err = write.Close()
if err != nil {
return err
}
err = cmdLoad.Wait()
if err != nil {
return errors.Wrap(err, stderrLoad.String())
}
_, err = io.Copy(os.Stdout, &buffer)
if err != nil {
return err
}
However because of the way the commands are piped, if there is a problem with e.g. the SSH key or WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! error presents itself when SSHing to the instance, the functions just hangs endlessly on the cmdSave.Wait() and no output is displayed, leaving the user unaware of what the problem is.
Is there a way to do this so that the output isn't swallowed and the function isn't left hanging?