Resolving dependencies...
Configuring mtl-2.2.1...
Configuring syb-0.6...
Building syb-0.6...
Building mtl-2.2.1...
Installed syb-0.6
Installed mtl-2.2.1
Downloading singletons-0.8.4...
Configuring singletons-0.8.4...
Building singletons-0.8.4...
Failed to install singletons-0.8.4
Build log ( /home/builder/.cabal/logs/singletons-0.8.4.log ):
cabal: Entering directory '/tmp/cabal-tmp-3566/singletons-0.8.4'
Configuring singletons-0.8.4...
Building singletons-0.8.4...
Preprocessing library singletons-0.8.4...
[1 of 7] Compiling Data.Singletons.Util ( Data/Singletons/Util.hs, dist/build/Data/Singletons/Util.o )

Data/Singletons/Util.hs:178:5: error:
    • The constructor ‘DataD’ should have 6 arguments, but has been given 5
    • In the pattern: DataD _cxt _name tvbs cons _derivings
      In a case alternative:
          DataD _cxt _name tvbs cons _derivings -> return (tvbs, cons)
      In a stmt of a 'do' block:
        case dec of {
          DataD _cxt _name tvbs cons _derivings -> return (tvbs, cons)
          NewtypeD _cxt _name tvbs con _derivings -> return (tvbs, [con])
          _ -> badDeclaration }
cabal: Leaving directory '/tmp/cabal-tmp-3566/singletons-0.8.4'
cabal: Error: some packages failed to install:
singletons-0.8.4 failed during the building phase. The exception was:
ExitFailure 1