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...
Configuring singletons-0.8...
Building singletons-0.8...
Failed to install singletons-0.8
Build log ( /home/builder/.cabal/logs/singletons-0.8.log ):
cabal: Entering directory '/tmp/cabal-tmp-21856/singletons-0.8'
Configuring singletons-0.8...
Building singletons-0.8...
Preprocessing library singletons-0.8...
[1 of 6] Compiling Singletons.Util  ( Singletons/Util.hs, dist/build/Singletons/Util.o )
[2 of 6] Compiling Singletons.Promote ( Singletons/Promote.hs, dist/build/Singletons/Promote.o )

Singletons/Promote.hs:143:29: error:
    Not in scope: data constructor ‘FamilyD’
    Perhaps you meant ‘FamilyI’ (imported from Language.Haskell.TH)

Singletons/Promote.hs:265:18: error:
    Not in scope: data constructor ‘FamilyD’
    Perhaps you meant ‘FamilyI’ (imported from Language.Haskell.TH)
cabal: Leaving directory '/tmp/cabal-tmp-21856/singletons-0.8'
cabal: Error: some packages failed to install:
singletons-0.8 failed during the building phase. The exception was:
ExitFailure 1