Still not a fan. These seem like schemes for people who are annoyed by errors, and just throw them over the wall... similar to say putting an entire python block in a try/except.
With any sufficiently large application you start to realize how awful that is, especially when something fails and the only log is 'EOF'.
I've learned to treat errors as first class citizens, because they are. I always add an annotation and stack entry via wrappers before returning them. Unless I'm missing something, that seems all but impossible with these schemes.
