Weirdly, on one of the machines I use, the localhost ip assigned to lo isn't being assigned to 127.0.0.1. When running make test, the install will fail if 127.0.0.1 ip address is not available. Specifically, the t/local/referrer test will cause the machine to hang, after a can't connect to 127.0.0.1:(port) (Connection timed out) at t/local/referrer.t line 39. You may be able to use IO::Interface::Simple to check to see if the interface exists.