Resolving dependencies...
Downloading permutation-0.5.0...
[1 of 1] Compiling Main             ( /tmp/permutation-0.5.0-18964/permutation-0.5.0/Setup.lhs, /tmp/permutation-0.5.0-18964/permutation-0.5.0/dist/setup/Main.o )

/tmp/permutation-0.5.0-18964/permutation-0.5.0/Setup.lhs:13:11: Warning:
    In the use of `runTests'
    (imported from Distribution.Simple, but defined in Distribution.Simple.UserHooks):
    Deprecated: "Please use the new testing interface instead!"
Linking /tmp/permutation-0.5.0-18964/permutation-0.5.0/dist/setup/setup ...
Configuring permutation-0.5.0...
Building permutation-0.5.0...
Preprocessing library permutation-0.5.0...

lib/Data/IntArray.hs:42:0:
     warning: extra tokens at end of #ifdef directive [enabled by default]
[ 1 of 13] Compiling Data.IntArray    ( lib/Data/IntArray.hs, dist/build/Data/IntArray.o )

lib/Data/IntArray.hs:43:18:
    Module `GHC.Exts' does not export `isTrue#'
Failed to install permutation-0.5.0
cabal: Error: some packages failed to install:
permutation-0.5.0 failed during the building phase. The exception was:
ExitFailure 1