That's actually a great goal. Every time an application gives me "whoopsy, something went wrong" providing no useful information, it, um, gives me conniptions :) So I wasn't able to pass by and did some testing using virtualization to reproduce the cases (I only checked Netty, Jetty, and CIO). Sad to say, there were no actual exceptions that would've helped to identify a potential problem, the only useful thing I found was that little warning from Netty
[main] WARN i.netty.util.internal.MacAddressUtil - Failed to find a usable hardware address from the network interfaces; using random bytes
.