- When specifying an invalid value for a label, it was not always clear which label the value was specified for. Starting with this release, the label's key is included in such error messages, which makes debugging easier. ([#77144](https://github.com/kubernetes/kubernetes/pull/77144), [@kenegozi](https://github.com/kenegozi))

- The `kubelet` now reports distinguishes log messages about certificate rotation for its client cert and server cert separately to make debugging problems with one or the other easier. ([#101252](https://github.com/kubernetes/kubernetes/pull/101252), [@smarterclayton](https://github.com/smarterclayton))

- Exposed the `apiserver_watch_cache_resource_version` metric to simplify debugging problems with watchcache. ([#125377](https://github.com/kubernetes/kubernetes/pull/125377), [@wojtek-t](https://github.com/wojtek-t)) [SIG API Machinery and Instrumentation]

- Ephemeral containers have been added in alpha. These temporary containers can be added to running pods for purposes such as debugging, similar to how `kubectl exec` runs a process in an existing container. Also like `kubectl exec`, no resources are reserved for ephemeral containers and they are not restarted when they exit. Note that container namespace targeting is not yet implemented,...

### Support for cgroups v2 Graduates to Stable