How to reproduce:

1. Create the following code:

   
   <?php
   namespace K;
   use Exception;

function myMethod($b)
{
echo "$b";
$f = new \stdClass();
$f->xx = [$b, new Exception()];
return $f; //place breakpoint here
}

$foo = 1;
$a = myMethod(42); //place breakpoint here

2. Start debugger
On the first breakpoint hit, the local variable `$foo` will be shown in Watches.
3. Press _Resume Program_, 
4. On breakpoint, press _Step Into_

There will be no local variable `$foo`.