wavetermdev/waveterm · warning

cancelled while waiting for app port: %w

Error message

cancelled while waiting for app port: %w

What it means

While waiting for the builder app's port, runBuilderApp also watches the caller's context. If the context is cancelled (user cancelled the build, block closed, app shutdown), the subprocess is killed and this error wraps ctx.Err() (context.Canceled or context.DeadlineExceeded).

Source

Thrown at pkg/buildercontroller/buildercontroller.go:411

		}
	}()

	timeout := time.NewTimer(5 * time.Second)
	defer timeout.Stop()

	select {
	case port := <-portChan:
		process.Port = port
		return process, nil
	case err := <-errChan:
		cmd.Process.Kill()
		return nil, err
	case <-timeout.C:
		cmd.Process.Kill()
		return nil, fmt.Errorf("timeout waiting for port")
	case <-ctx.Done():
		cmd.Process.Kill()
		return nil, fmt.Errorf("cancelled while waiting for app port: %w", ctx.Err())
	}
}

func (bc *BuilderController) handleBuildError(err error, resultCh chan<- *BuildResult) {
	bc.lock.Lock()
	defer bc.lock.Unlock()
	bc.setStatus_nolock(BuilderStatus_Error, 0, 1, err.Error())

	if resultCh != nil {
		buildOutput := ""
		if bc.outputBuffer != nil {
			lines := bc.outputBuffer.GetLines()
			buildOutput = strings.Join(lines, "\n")
		}
		select {
		case resultCh <- &BuildResult{
			Success:      false,
			ErrorMessage: err.Error(),

View on GitHub (pinned to a4447c1563)

Solutions

1. Confirm the cancellation was intentional (block closed / user cancel); if so, no action needed
2. If unintended, check ancestor context deadlines that expire during startup
3. Retry the build with a fresh context if the cancellation was accidental

process, err := bc.runBuilderApp(ctx, ...)
if err != nil {
    if errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) {
        return nil // expected on cancel/shutdown; clean up quietly
    }
    return err
}

When it happens

Trigger: ctx.Done() fires during the 5-second port wait — caller cancellation, block teardown, or a context deadline set by an ancestor expiring.

Common situations: User closes the terminal block or cancels the run while the builder app is starting; Wave shutdown cancels in-flight builds; upstream deadline shorter than the 5s port wait.

Related errors

• failed to create stdout pipe: %w
• failed to create stderr pipe: %w
• failed to create stdin pipe: %w
• failed to start process: %w
• process died before emitting port

AI-assisted analysis of wavetermdev/waveterm@a4447c1563 (2026-09-01). Data as JSON: /api/errors/726e916866fcef04. Report an issue: GitHub.