Use absolute path for tarball destination file

pkg/cmd/builder/build.go

@@ -108,7 +108,7 @@ func Build(ctx context.Context, client *containerd.Client, options types.Builder
 		// Open the tar file
 		reader, err := os.Open(buildCtlArgs.DestFile)
 		if err != nil {
-			return fmt.Errorf("Failed to open file destination file: %v", err)
+			return fmt.Errorf("failed to open file destination file: %v", err)
 		}
 		defer reader.Close()
 
@@ -187,7 +187,6 @@ func loadImage(ctx context.Context, in io.Reader, namespace, address, snapshotte
 	if err != nil {
 		if r.N == 0 {
 			// Avoid confusing "unrecognized image format"
-			log.L.Debugf("no image was built. error: %v", err)
 			return errors.New("no image was built")
 		}
 		if errors.Is(err, images.ErrEmptyWalk) {
@@ -234,11 +233,10 @@ func generateBuildctlArgs(ctx context.Context, client *containerd.Client, option
 	result.BuildctlBinary = buildctlBinary
 
 	// Set the default destination file
-	var defaultDestFile = "output.tar"
-	// defaultDestFile, err := filepath.Abs("output.tar")
-	// if err != nil {
-	// 	return result, fmt.Errorf("failed to set the default destination file path: %v", err)
-	// }
+	defaultDestFile, err := filepath.Abs("output.tar")
+	if err != nil {
+		return result, fmt.Errorf("failed to set the default destination file path: %v", err)
+	}
 
 	output := options.Output
 	if output == "" {
@@ -308,7 +306,6 @@ func generateBuildctlArgs(ctx context.Context, client *containerd.Client, option
 		_, destFilePath, _ := strings.Cut(output, "dest=")
 		result.DestFile = destFilePath
 	}
-	log.L.Debugf("\n------------output: %s\n--------------", output)
 
 	buildctlArgs := buildkitutil.BuildctlBaseArgs(options.BuildKitHost)
 	buildctlArgs = append(buildctlArgs, []string{