Why has the behavior of if changed?

Question

go

func ErrKeyNotExists() error {
  return errors.New("key not exists")
}

if ErrKeyNotExists() == ErrKeyNotExists() {
  log.Println("ok")
} else {
  log.Println("err")
}

Why does it return "err"? I have a lot of such functions in my code, and after updating to 1.7 everything broke.
UPD.
Because errors returns a reference, the if looks for the same address, not the value.
Checked with this code

q := 1
w := 1
if &q == &w {
  log.Println("ok")
} else {
  log.Println("err")
}

How to force if to compare value?

Answer 1

if ErrKeyNotExists().Error() == ErrKeyNotExists().Error() {
If nil can be returned, then additional checks must be done.