- Kubectl: The deprecated `kubectl alpha debug` command is removed. Use `kubectl debug` instead. ([#98111](https://github.com/kubernetes/kubernetes/pull/98111), [@pandaamanda](https://github.com/pandaamanda)) [SIG CLI]

Users who create ephemeral containers using `kubectl debug` should note that kubectl version 1.22 will attempt to fall back to the old API; older versions of kubectl will not work with cluster versions of 1.22 or later. Please update kubectl to 1.22 if you wish to use `kubectl debug` with a mix of cluster versions.

## Known Issues

pkg database/sql, type NullTime struct, Valid bool
pkg debug/dwarf, method (*UnsupportedType) Common() *CommonType
pkg debug/dwarf, method (*UnsupportedType) Size() int64
pkg debug/dwarf, method (*UnsupportedType) String() string
pkg debug/dwarf, type UnsupportedType struct
pkg debug/dwarf, type UnsupportedType struct, embedded CommonType
pkg debug/dwarf, type UnsupportedType struct, Tag Tag
pkg debug/elf, type Symbol struct, Library string

- `kubectl alpha debug` command now supports debugging pods by copy the original one. ([#90094](https://github.com/kubernetes/kubernetes/pull/90094), [@aylei](https://github.com/aylei)) [SIG CLI]

* Exposed `/debug/flags/v` to allow dynamically set glog logging level.  For example, to change glog level to 3, send a PUT request such as `curl -X PUT http://127.0.0.1:8080/debug/flags/v -d "3"`. ([#63777](https://github.com/kubernetes/kubernetes/pull/63777), [@hzxuzhonghu](https://github.com/hzxuzhonghu))

   ([#123413](https://github.com/kubernetes/kubernetes/pull/123413), [@seans3](https://github.com/seans3))
- A new flag called `custom` has been introduced in `kubectl debug`, allowing users to customize pre-defined profiles. ([#120346](https://github.com/kubernetes/kubernetes/pull/120346), [@ardaguclu](https://github.com/ardaguclu))

    *   tf.data input pipelines can now be executed in debug mode, which
        disables any asynchrony, parallelism, or non-determinism and forces
        Python execution (as opposed to trace-compiled graph execution) of
        user-defined functions passed into transformations such as `map`. The
        debug mode can be enabled through
        `tf.data.experimental.enable_debug_mode()`.
*   `tf.lite`

- The apiserver debug endpoint `/debug/api_priority_and_fairness/dump_requests` has been extended to dump executing requests as well as queued ones.  A column for StartTime has been added to the returned table, with the queued requests having a StartTime of "0001-01-01T00:00:00Z"....

  // When we turn on grappler, confirm that the tf.Add has been rewritten into a
  // tf.Mul.
  // This capability of checking the executed op names is currently only enabled
  // for TFRT debug build, for performance and simplicity reasons.
  if (use_tfrt) {
    TF_Buffer* buf = TF_NewBuffer();
    TFE_GetExecutedOpNames(ctx, buf, status);
    ASSERT_EQ(TF_OK, TF_GetCode(status)) << TF_Message(status);

pkg reflect, method (Value) Slice3(int, int, int) Value
pkg runtime, type MemStats struct, GCSys uint64
pkg runtime, type MemStats struct, OtherSys uint64
pkg runtime/debug, func SetMaxStack(int) int
pkg runtime/debug, func SetMaxThreads(int) int
pkg sort, func Stable(Interface)
pkg strings, func IndexByte(string, uint8) int
pkg sync/atomic, func SwapInt32(*int32, int32) int32