> I get "attempt to yield across metamethod/C-call boundary"
> error.
> But I don't use any C-calls or metamethods in my
> application so I am baffled.
It is indeed possible to nest coroutines:
Are you by chance trying to yield from an iterator?
After digging through the code, I discovered I accidentally called "coroutine.wrap(function())" instead of "coroutine.wrap(function)", the result of which was this bizarre (to me) error. Thank you for pointing me in the right direction.