VS Code,如何显示堆栈跟踪

Edit: the following OP was not for display stack trace in VS Code. Will clean it up when the question is answered.

- - - OP  - - - 

I think I've already found how to display stack trace in VS Code, in which it says,

When you issue the k, kb, kp, kP, or kv command, a stack trace is displayed in a tabular format. If line loading is enabled, source modules and line numbers are also displayed.

However, I am just not able to make it working. This is what I get:

k
Unable to eval expression: "could not find symbol value for k"
Failed to eval expression:  {
 "symbol": "k",
 "scope": {
  "goroutineID": 1,
  "frame": 0
 }
} 

Eval error: could not find symbol value for k
kb
Unable to eval expression: "could not find symbol value for kb"
Failed to eval expression:  {
 "symbol": "kb",
 "scope": {
  "goroutineID": 1,
  "frame": 0
 }
} 

Eval error: could not find symbol value for kb

~. k c
Unable to eval expression: "1:1: illegal character U+007E '~'"
Failed to eval expression:  {
 "symbol": "~. k c",
 "scope": {
  "goroutineID": 1,
  "frame": 0
 }
} 

Eval error: 1:1: illegal character U+007E '~'

What I'm missing?