*** setup configure Configuring bytestring-class-0.0.0... Dependency base -any: using base-4.4.1.0 Dependency bytestring -any: using bytestring-0.9.2.0 Dependency utf8-string -any: using utf8-string-0.3.7 Using Cabal-1.12.0 compiled by ghc-7.2 Using compiler: ghc-7.2.2 Using install prefix: /usr/local/tmp/archive/install Binaries installed in: /usr/local/tmp/archive/install/bin Libraries installed in: /usr/local/tmp/archive/install/lib/bytestring-class-0.0.0/ghc-7.2.2 Private binaries installed in: /usr/local/tmp/archive/install/libexec Data files installed in: /usr/local/tmp/archive/install/share/bytestring-class-0.0.0 Documentation installed in: /usr/local/tmp/archive/install/share/doc/bytestring-class-0.0.0 Using alex version 3.0.1 found on system at: /usr/bin/alex Using ar found on system at: /usr/bin/ar Using c2hs version 0.16.3 found on system at: /usr/bin/c2hs Using cpphs version 1.11 found on system at: /usr/bin/cpphs Using ffihugs found on system at: /usr/local/bin/ffihugs Using gcc version 4.6 found on system at: /usr/bin/gcc Using ghc version 7.2.2 found on system at: /usr/local/bin/ghc Using ghc-pkg version 7.2.2 found on system at: /usr/local/bin/ghc-pkg No greencard found Using haddock version 2.9.4 found on system at: /usr/local/bin/haddock Using happy version 1.18.6 found on system at: /usr/bin/happy No hmake found Using hsc2hs version 0.67 found on system at: /usr/local/bin/hsc2hs Using hscolour version 1.19 found on system at: /usr/bin/HsColour Using hugs found on system at: /usr/local/bin/hugs No jhc found Using ld found on system at: /usr/bin/ld No lhc found No lhc-pkg found No nhc98 found Using pkg-config version 0.26 found on system at: /usr/bin/pkg-config Using ranlib found on system at: /usr/bin/ranlib Using strip found on system at: /usr/bin/strip Using tar found on system at: /bin/tar No uhc found *** setup build creating dist/build creating dist/build/autogen Building bytestring-class-0.0.0... Preprocessing library bytestring-class-0.0.0... Building library... creating dist/build /usr/local/bin/ghc --make -package-name bytestring-class-0.0.0 -hide-all-packages -fbuilding-cabal-package -i -idist/build -i. -idist/build/autogen -Idist/build/autogen -Idist/build -optP-include -optPdist/build/autogen/cabal_macros.h -odir dist/build -hidir dist/build -stubdir dist/build -package-id base-4.4.1.0-1f81e4e7baf87af8ebbcf52b7bec2254 -package-id bytestring-0.9.2.0-6cd6a90f79cbe419ccff0712438db3e6 -package-id utf8-string-0.3.7-59b2f76bee525ef52325b9245e4fcf74 -O -Wall -XHaskell98 Data.ByteString.Class [1 of 1] Compiling Data.ByteString.Class ( Data/ByteString/Class.hs, dist/build/Data/ByteString/Class.o ) Data/ByteString/Class.hs:39:10: Illegal instance declaration for `StrictByteString String' (All instance types must be of the form (T a1 ... an) where a1 ... an are *distinct type variables*, and each type variable appears at most once in the instance head. Use -XFlexibleInstances if you want to disable this.) In the instance declaration for `StrictByteString String' Data/ByteString/Class.hs:55:10: Illegal instance declaration for `LazyByteString String' (All instance types must be of the form (T a1 ... an) where a1 ... an are *distinct type variables*, and each type variable appears at most once in the instance head. Use -XFlexibleInstances if you want to disable this.) In the instance declaration for `LazyByteString String'