% sudo port install ghc
--->  Fetching ghc
--->  Verifying checksum(s) for ghc
--->  Extracting ghc
--->  Applying patches to ghc
~% sudo port install hs-cabal
--->  Fetching hs-HTTP
--->  Verifying checksum(s) for hs-HTTP
--->  Extracting hs-HTTP
--->  Configuring hs-HTTP
--->  Building hs-HTTP with target all
Error: Target org.macports.build returned: shell command "cd /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_ports_devel_hs-HTTP/work/HTTP-3001.0.4 && runhaskell Setup build" returned error 1
Command output:              Inferred type: rotL :: forall a.
                                    (Data.Bits.Bits a) =>
                                    a -> Int -> a

Network/HTTP/MD5Aux.hs:89:9:
    Warning: No explicit method nor default method for `*'
    In the instance declaration for `Num ABCD'

Network/HTTP/MD5Aux.hs:89:9:
    Warning: No explicit method nor default method for `abs'
    In the instance declaration for `Num ABCD'

Network/HTTP/MD5Aux.hs:89:9:
    Warning: No explicit method nor default method for `signum'
    In the instance declaration for `Num ABCD'

Network/HTTP/MD5Aux.hs:89:9:
    Warning: No explicit method nor default method for `fromInteger'
    In the instance declaration for `Num ABCD'
[ 2 of 10] Compiling Network.HTTP.MD5 ( Network/HTTP/MD5.hs, dist/build/Network/HTTP/MD5.o )
[ 3 of 10] Compiling Network.HTTP.Base64 ( Network/HTTP/Base64.hs, dist/build/Network/HTTP/Base64.o )
[ 4 of 10] Compiling Network.Stream   ( Network/Stream.hs, dist/build/Network/Stream.o )
[ 5 of 10] Compiling Network.StreamDebugger ( Network/StreamDebugger.hs, dist/build/Network/StreamDebugger.o )
[ 6 of 10] Compiling Network.StreamSocket ( Network/StreamSocket.hs, dist/build/Network/StreamSocket.o )

Network/StreamSocket.hs:40:31:
    Class `Exception' used as a type
    In the type `Exception'
    In the type `Exception -> IO (Result a)'
    In the type `Socket -> Exception -> IO (Result a)'

Error: The following dependencies failed to build: hs-HTTP hs-libcabal hs-zlib
Error: Status 1 encountered during processing.