Method Start

scripts/develop/main.go:536–575

Start registers a long-running command with the group. It sets up graceful shutdown (SIGINT on context cancel, SIGKILL after timeout), wires stdout/stderr to structured logging, starts the process, and registers a goroutine that waits for it to exit.

(name string, cmd *exec.Cmd)

// timeout), wires stdout/stderr to structured logging, starts the
// process, and registers a goroutine that waits for it to exit.
func (g *procGroup) Start(name string, cmd *exec.Cmd) error {
	// Guard against nil env: appending to nil creates a non-nil
	// slice that exec.Cmd treats as an explicit (empty) env.
	if cmd.Env == nil {
		cmd.Env = os.Environ()
	}
	cmd.Env = append(cmd.Env, "FORCE_COLOR=1")

	// Run in a new process group so signals reach the entire
	// child tree (e.g. pnpm → vite), not just the direct child.
	cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}

	// Graceful shutdown: SIGINT the process group on context
	// cancel, escalate to SIGKILL after WaitDelay.
	cmd.Cancel = func() error {
		return syscall.Kill(-cmd.Process.Pid, syscall.SIGINT)
	}
	cmd.WaitDelay = shutdownTimeout

	named := g.logger.Named(name)
	w := &logWriter{logger: named}
	cmd.Stdout = w
	cmd.Stderr = w

	named.Info(g.ctx, "starting", slog.F("cmd", strings.Join(cmd.Args, " ")))
	if err := cmd.Start(); err != nil {
		return xerrors.Errorf("starting %s: %w", name, err)
	}

	g.eg.Go(func() error {
		err := cmd.Wait()
		if err != nil {
			return xerrors.Errorf("process %q exited: %w", name, err)
		}
		// Clean exit is still unexpected for a long-running dev
		// process. Report it so the orchestrator shuts down.
		return xerrors.Errorf("process %q exited unexpectedly", name)
	})
	return nil
}

// Wait blocks until all started processes have exited.
func (g *procGroup) Wait() error { return g.eg.Wait() }