diff --git a/commands/build.go b/commands/build.go
index 60fbb4272..93791a4ac 100644
--- a/commands/build.go
+++ b/commands/build.go
@@ -425,7 +425,7 @@ func runBasicBuild(ctx context.Context, dockerCli command.Cli, opts *cbuild.Opti
 	return resp, dfmap, err
 }
 
-func runControllerBuild(ctx context.Context, dockerCli command.Cli, opts *cbuild.Options, options buildOptions, printer *progress.Printer) (*client.SolveResponse, *build.Inputs, error) {
+func runControllerBuild(ctx context.Context, dockerCli command.Cli, opts *cbuild.Options, options buildOptions, printer *progress.Printer) (_ *client.SolveResponse, _ *build.Inputs, retErr error) {
 	if options.invokeConfig != nil && (options.dockerfileName == "-" || options.contextPath == "-") {
 		// stdin must be usable for monitor
 		return nil, nil, errors.Errorf("Dockerfile or context from stdin is not supported with invoke")
@@ -434,29 +434,12 @@ func runControllerBuild(ctx context.Context, dockerCli command.Cli, opts *cbuild
 	c := local.NewController(ctx, dockerCli)
 	defer c.Close()
 
-	var (
-		ref    string
-		retErr error
-
-		f  *ioset.SingleForwarder
-		pr io.ReadCloser
-		pw io.WriteCloser
-	)
-
+	var in io.ReadCloser
 	if options.invokeConfig == nil {
-		pr = dockerCli.In()
-	} else {
-		f = ioset.NewSingleForwarder()
-		f.SetReader(dockerCli.In())
-		pr, pw = io.Pipe()
-		f.SetWriter(pw, func() io.WriteCloser {
-			pw.Close() // propagate EOF
-			logrus.Debug("propagating stdin close")
-			return nil
-		})
+		in = dockerCli.In()
 	}
 
-	resp, inputs, err := c.Build(ctx, opts, pr, printer)
+	resp, inputs, err := c.Build(ctx, opts, in, printer)
 	if err != nil {
 		var be *controllererrors.BuildError
 		if errors.As(err, &be) {
@@ -467,28 +450,26 @@ func runControllerBuild(ctx context.Context, dockerCli command.Cli, opts *cbuild
 		}
 	}
 
-	if options.invokeConfig != nil {
-		if err := pw.Close(); err != nil {
-			logrus.Debug("failed to close stdin pipe writer")
-		}
-		if err := pr.Close(); err != nil {
-			logrus.Debug("failed to close stdin pipe reader")
-		}
-	}
-
 	if options.invokeConfig != nil && options.invokeConfig.needsDebug(retErr) {
 		// Print errors before launching monitor
 		if err := printError(retErr, printer); err != nil {
 			logrus.Warnf("failed to print error information: %v", err)
 		}
 
-		pr2, pw2 := io.Pipe()
-		f.SetWriter(pw2, func() io.WriteCloser {
-			pw2.Close() // propagate EOF
+		pr, pw := io.Pipe()
+
+		f := ioset.NewSingleForwarder()
+		f.SetReader(dockerCli.In())
+		f.SetWriter(pw, func() io.WriteCloser {
+			pw.Close() // propagate EOF
 			return nil
 		})
-		monitorBuildResult, err := options.invokeConfig.runDebug(ctx, ref, opts, c, pr2, os.Stdout, os.Stderr, printer)
-		if err := pw2.Close(); err != nil {
+
+		// TODO: ref was never set to a value in the original code. Removed the variable to
+		// reduce confusion but it also probably means this call is wrong in some way.
+		// This area should be removed during the refactor anyway so it doesn't matter that much.
+		monitorBuildResult, err := options.invokeConfig.runDebug(ctx, "", opts, c, pr, os.Stdout, os.Stderr, printer)
+		if err := pw.Close(); err != nil {
 			logrus.Debug("failed to close monitor stdin pipe reader")
 		}
 		if err != nil {
diff --git a/monitor/monitor.go b/monitor/monitor.go
index 6156dc834..50cabd672 100644
--- a/monitor/monitor.go
+++ b/monitor/monitor.go
@@ -346,10 +346,6 @@ func (m *monitor) invoke(ctx context.Context, pid string, cfg *controllerapi.Inv
 
 func (m *monitor) Close() error {
 	m.cancelRunningProcesses()
-	// if m.buildConfig.resultCtx != nil {
-	// 	b.buildConfig.resultCtx.Done()
-	// }
-	// TODO: cancel ongoing builds?
 	return nil
 }