fix: record last error when calling processDir

cmd/um/main.go

@@ -143,6 +143,7 @@ func appMain(c *cli.Context) (err error) {
 	}
 
 	proc := &processor{
+		errorCount:      0,
 		outputDir:       output,
 		skipNoopDecoder: c.Bool("skip-noop"),
 		removeSource:    c.Bool("remove-source"),
@@ -170,6 +171,7 @@ type processor struct {
 	removeSource    bool
 	updateMetadata  bool
 	overwriteOutput bool
+	errorCount      int
 }
 
 func (p *processor) watchDir(inputDir string) error {
@@ -231,6 +233,8 @@ func (p *processor) processDir(inputDir string) error {
 	if err != nil {
 		return err
 	}
+
+	var lastError error = nil
 	for _, item := range items {
 		if item.IsDir() {
 			continue
@@ -238,10 +242,11 @@ func (p *processor) processDir(inputDir string) error {
 
 		filePath := filepath.Join(inputDir, item.Name())
 		if err := p.processFile(filePath); err != nil {
+			lastError = err
 			logger.Error("conversion failed", zap.String("source", item.Name()), zap.Error(err))
 		}
 	}
-	return nil
+	return lastError
 }
 
 func (p *processor) processFile(filePath string) error {