List Comprehensions: undefined existing list

I wonder why this isn't reported yet, maybe I'm missing something?

```
var lst = [0, 1, 2];
var lst2 = [n*n for n in lst];
```

I expect `lst2` to equal `[0, 1, 4]`, but compilation fails with

```
line 2 col 26 undefined lst
var lst2 = [n*2 for n in lst];
^^^
```