defining `fail = error` for SIO, with a `HasCallStack` so that when we fail to
match in a do block we immediately alert the caller and have a callstack.

this is fine to do in testing since this can be a form of test in and of itself

example:
```
test = do
  [oneElem] <- getListOfThings
  -- ^ if this doesn't return exactly one element, we'll fail out
  doWithOneElem oneElem
```