Layout errors crash REPL

foo.ctt:
```
-}
```

```
> :l foo.ctt
Exception: Parse failed in "foo.ctt"
cubical: Layout error: Found } at (138,2) without an explicit layout block.
CallStack (from HasCallStack):
  error, called at ./Exp/Layout.hs:102:23 in main:Exp.Layout
$ 
```
