The create-swank-server function in swank-cmucl.lisp has been changed from doing:
(system:add-fd-handler fd :input #'accept-connection)
into just doing:
(accept-connection fd)
This means one must enable multi-processing to run slime. I /think/ the former method is more efficient, but I guess that's marginal. The fact that local set up can more easily break slime is a real downside though. So what's the upside to this change?