testing.T.Log is not meant to be used anymore after the test for which the testing.T instance was created has returned. This affects tests which do not properly terminate all goroutines. While such tests ideally should get fixed, it may not be possible in all cases. For example, Kubernetes has several APIs which create goroutines without properly supporting cleanup.

It would be good to support safe usage of logr.testing also for such tests.

Found in Kubernetes for klog.ktesting, which is conceptually similar - see kubernetes/kubernetes#110811 for the original report and kubernetes/klog#337 for a potential solution.