Resolving dependencies...
Configuring peano-0.1.0.1...
Building peano-0.1.0.1...
Installed peano-0.1.0.1
Configuring natural-induction-0.1.0.1...
Building natural-induction-0.1.0.1...
Failed to install natural-induction-0.1.0.1
Build log ( /home/builder/.cabal/logs/natural-induction-0.1.0.1.log ):
cabal: Entering directory '/tmp/cabal-tmp-1875/natural-induction-0.1.0.1'
Configuring natural-induction-0.1.0.1...
Building natural-induction-0.1.0.1...
Preprocessing library natural-induction-0.1.0.1...
cabal: can't find source for Data/Natural/Class in ., dist/build/autogen
cabal: Leaving directory '/tmp/cabal-tmp-1875/natural-induction-0.1.0.1'
cabal: Error: some packages failed to install:
natural-induction-0.1.0.1 failed during the building phase. The exception was:
ExitFailure 1