code: func (s *Action) GitCredentialConfigure(ctx context.Context, c *cli.Context) error {
  	flags := 0
  	flag := "--global"
  	if c.Bool("local") {
  		flag = "--local"
  		flags++
  	}
  	if c.Bool("global") {
  		flag = "--global"
  		flags++
  	}
  	if c.Bool("system") {
  		flag = "--system"
  		flags++
  	}
  	if flags >= 2 {
  		return ExitError(ctx, ExitUnsupported, nil, "Error: only specify one target of installation!")
  	}
  	if flags == 0 {
  		log.Println("No target given, assuming --global.")
  	}
  	cmd := exec.Command("git", "config", flag, "credential.helper", `"!gopass git-credential $@"`)
  	cmd.Stdout = os.Stdout
  	cmd.Stderr = os.Stderr
  	return cmd.Run()
  }
docs: // GitCredentialConfigure configures gopass as git's credential.helper