Hi, I encountered a problem with Network.Socket in MacOS 10.5 Here is the code that I am testing, ----------------------------------------- ----------------------------------------- module Main where import qualified Network.Socket as Socket main :: IO () main = do { (hostname, _) <- Socket.getNameInfo [] True False (Socket.SockAddrUnix "localhost") -- (hostname, _) <- Socket.getNameInfo [] True False (Socket.SockAddrInet 9000 (127 + 0 * 256 + 0 * 256^2 + 1 * 256^3)) ; putStrLn (show hostname) } Running the above code yields the following error ghc --make -O2 TestSocket.hs [1 of 1] Compiling Main ( TestSocket.hs, TestSocket.o ) Linking TestSocket ... $ ./TestSocket TestSocket: getNameInfo: does not exist (ai_family not supported) If I switch to SockAddrInet instead, the error is gone. I am using GHC 6.10.3 and Network 2.2.1 Regards, Kenny