Resolving dependencies...
Configuring mtl-2.2.1...
Configuring syb-0.6...
Building mtl-2.2.1...
Building syb-0.6...
Installed syb-0.6
Installed mtl-2.2.1
Downloading singletons-0.8.6...
Configuring singletons-0.8.6...
Building singletons-0.8.6...
Failed to install singletons-0.8.6
Build log ( /home/builder/.cabal/logs/singletons-0.8.6.log ):
cabal: Entering directory '/tmp/cabal-tmp-14413/singletons-0.8.6'
Configuring singletons-0.8.6...
Building singletons-0.8.6...
Preprocessing library singletons-0.8.6...
[1 of 7] Compiling Data.Singletons.Util ( Data/Singletons/Util.hs, dist/build/Data/Singletons/Util.o )

Data/Singletons/Util.hs:134:17: error:
    Not in scope: data constructor ‘RoledTV’

Data/Singletons/Util.hs:135:17: error:
    Not in scope: data constructor ‘KindedRoledTV’

Data/Singletons/Util.hs:143:17: error:
    Not in scope: data constructor ‘RoledTV’

Data/Singletons/Util.hs:144:17: error:
    Not in scope: data constructor ‘KindedRoledTV’
cabal: Leaving directory '/tmp/cabal-tmp-14413/singletons-0.8.6'
cabal: Error: some packages failed to install:
singletons-0.8.6 failed during the building phase. The exception was:
ExitFailure 1