Resolving dependencies...
Configuring readline-1.0.3.0...
Configuring mtl-2.2.1...
Building mtl-2.2.1...
Building readline-1.0.3.0...
Configuring text-1.2.2.1...
Installed mtl-2.2.1
Installed readline-1.0.3.0
Building text-1.2.2.1...
Installed text-1.2.2.1
Configuring parsec-3.1.11...
Building parsec-3.1.11...
Installed parsec-3.1.11
Downloading CPL-0.0.7...
Configuring CPL-0.0.7...
Building CPL-0.0.7...
Failed to install CPL-0.0.7
Build log ( /home/builder/.cabal/logs/CPL-0.0.7.log ):
cabal: Entering directory '/tmp/cabal-tmp-13194/CPL-0.0.7'
Configuring CPL-0.0.7...
Building CPL-0.0.7...
Preprocessing executable 'cpl' for CPL-0.0.7...
[ 1 of 18] Compiling Variance         ( src/Variance.hs, dist/build/cpl/cpl-tmp/Variance.o )
[ 2 of 18] Compiling Paths_CPL        ( dist/build/autogen/Paths_CPL.hs, dist/build/cpl/cpl-tmp/Paths_CPL.o )
[ 3 of 18] Compiling ParserUtils      ( src/ParserUtils.hs, dist/build/cpl/cpl-tmp/ParserUtils.o )
[ 4 of 18] Compiling Funct            ( src/Funct.hs, dist/build/cpl/cpl-tmp/Funct.o )
[ 5 of 18] Compiling CDT[boot]        ( src/CDT.hs-boot, dist/build/cpl/cpl-tmp/CDT.o-boot )
[ 6 of 18] Compiling FE               ( src/FE.hs, dist/build/cpl/cpl-tmp/FE.o )
[ 7 of 18] Compiling Subst            ( src/Subst.hs, dist/build/cpl/cpl-tmp/Subst.o )

src/Subst.hs:31:1: warning: [-Wdeprecations]
    Module ‘Control.Monad.Error’ is deprecated:
      Use Control.Monad.Except instead
[ 8 of 18] Compiling Type             ( src/Type.hs, dist/build/cpl/cpl-tmp/Type.o )
[ 9 of 18] Compiling CDT              ( src/CDT.hs, dist/build/cpl/cpl-tmp/CDT.o )

src/CDT.hs:206:9: error:
    • Non type-variable argument in the constraint: Subst.FEs (GenFE t)
      (Use FlexibleContexts to permit this)
    • When checking the inferred type
        f :: forall t t1. Subst.FEs (GenFE t) => (t1, GenType t) -> Bool
      In an equation for ‘isUnconditioned’:
          isUnconditioned
            = all f natDecls
            where
                f (_, dom :-> cod)
                  = case t of {
                      LeftObject -> 0 `notElem` tv dom
                      RightObject -> 0 `notElem` tv cod }
      In an equation for ‘mkCDT’:
          mkCDT t functName functArity factName natDecls
            = object
            where
                object
                  = CDT
                      {objectType = t, nats = nats, nNats = length (natDecls),
                       isUnconditioned = isUnconditioned, functName = functName,
                       functVariance = vs, functArity = functArity, factName = factName,
                       factParams = map snd natDecls, factDestType = factDestType}
                vs
                  = map joinL . transpose . map f $ natDecls
                  where
                      f (_, dom :-> cod)
                        = zipWith
                            g
                            (tail (variance (CFE (1 + functArity) dom)))
                            (tail (variance (CFE (1 + functArity) cod)))
                      g = ...
                factDestType
                  = case t of {
                      LeftObject -> a :-> b
                      RightObject -> b :-> a }
                  where
                      a = Ap object ...
                      b = Var 0
                nats
                  = zipWith f natDecls [0 .. ]
                  where
                      f (name, declType@(dom :-> cod)) idx
                        = nat
                        where
                            ...
                ....
cabal: Leaving directory '/tmp/cabal-tmp-13194/CPL-0.0.7'
cabal: Error: some packages failed to install:
CPL-0.0.7 failed during the building phase. The exception was:
ExitFailure 1