This is a failing example that's close to what I was using.

I'm not sure if the problem is with stat or catchException, but essentially this is the problem:

You can use catchException to discharge an EXCEPTION assumption from your program. Great! If we use enough catchExceptions, the compiler tells us (assuming everything was well-typed) that our program won't have any uncaught exceptions at runtime.

Except it does. catchException doesn't ... catch the exception ... when using stat on a path that doesn't exist.

This threw me for a loop since I was assuming that uncaught runtime exceptions wouldn't happen.