I think it might be useful to have spy be able to take a message to be logged in addition to the data. (or have a similar macro showing an optional message instead of the code).

(spy "doing x" (blah))
(spy :doing-x (blah) ; because it is easier to type sometimes

with spy this may conflict with the log-level.

I find this sort of function with a message useful and use it quite often. Much more often than plain logging. Generally - I would't log the code unless it logged file and line number too.