x/tools/shadow: shadowing predefined identifiers is not detected?

[leovct]

Hi, I'm currently reading the Learning Go book and I came across the Shadowing variables section where it's mentioned that the go tool shadow does not catch shadowing predefined identifiers. I wanted to know why it was not implemented and if that's something planned, how can I help :slight_smile:

Here's a simple example

package main

import "fmt"

func main() {
    fmt.Println(true)
    true := "hey"
    fmt.Println(true)
}

$ go run main.go
true
hey // "true" identifier shadowed!

$ shadow main.go
// no errors detected :(

[seankhliao]

Duplicate of #33567