Resolving dependencies... Downloading kqueue-0.1.2.6... Configuring kqueue-0.1.2.6... Building kqueue-0.1.2.6... Preprocessing library kqueue-0.1.2.6... dist/build/System/KQueue.chs.h:2:23: fatal error: sys/event.h: No such file or directory compilation terminated. c2hs: Error during preprocessing custom header file Failed to install kqueue-0.1.2.6 cabal: Error: some packages failed to install: kqueue-0.1.2.6 failed during the building phase. The exception was: ExitFailure 1