Comment by peter-fogg

In this case, the dragon is slain without much trouble. In LVish (https://github.com/iu-parfunc/lvars) we've got an effect-tracking system that allows us to ensure determinism (read more here: http://www.cs.indiana.edu/~lkuper/papers/dissertation-draft-...). This would be pretty easily extended to only allow computations that are safe to log. And this is all in GHC Haskell! No external static analysis is necessary; the compiler can do it for us.