remove the enforcement of fmt.Stringer

pkg/internal/controller/controller.go

@@ -175,7 +175,16 @@ func (c *Controller[request]) Start(ctx context.Context) error {
 		// caches.
 		errGroup := &errgroup.Group{}
 		for _, watch := range c.startWatches {
-			log := c.LogConstructor(nil).WithValues("source", watch.String())
+			log := c.LogConstructor(nil)
+			_, ok := watch.(interface {
+				String() string
+			})
+
+			if !ok {
+				log = log.WithValues("source", fmt.Sprintf("%T", watch))
+			} else {
+				log = log.WithValues("source", fmt.Sprintf("%s", watch))
+			}
 			didStartSyncingSource := &atomic.Bool{}
 			errGroup.Go(func() error {
 				// Use a timeout for starting and syncing the source to avoid silently

pkg/source/source.go

@@ -56,10 +56,6 @@ type TypedSource[request comparable] interface {
 	// Start is internal and should be called only by the Controller to start the source.
 	// Start must be non-blocking.
 	Start(context.Context, workqueue.TypedRateLimitingInterface[request]) error
-
-	// String enforces the custom source to adhere to the fmt.Stringer interface
-	// to print when being logged.
-	String() string
 }
 
 // SyncingSource is a source that needs syncing prior to being usable. The controller