This is all I have to go on. Let me know if there's anything I can do to help figure this out. I had a server running for a few days with -N2, handling about 1000 requests/second. It took a long while to get to this error, so reproducing it is probably not a trivial thing to do.
server-name: server-name: schedule: re-entered unsafely.
Perhaps a 'foreign import unsafe' should be 'safe'?
NetworkziLibev_d1yN: Return code (0) not ok
I am using libev-0.4.0, snap-0.8.0.2, snap-core-0.8.1, snap-server-0.8.1.1, libev 4.03, and ghc 7.0.4.
We're getting rid of the libev backend for 0.9, because of issues like this and because the slight increase in performance is not worth the burden of maintaining a separate parallel server backend. I suggest just switching to the normal backend, which is nearly as fast anyways.