Resolving dependencies...
cabal: Entering directory '/tmp/cabal-tmp-21829/split-0.2.3.1'
Configuring split-0.2.3.1...
Building split-0.2.3.1...
Preprocessing library split-0.2.3.1...
[1 of 2] Compiling Data.List.Split.Internals ( src/Data/List/Split/Internals.hs, dist/build/Data/List/Split/Internals.o )
[2 of 2] Compiling Data.List.Split  ( src/Data/List/Split.hs, dist/build/Data/List/Split.o )
Running Haddock for split-0.2.3.1...
Running hscolour for split-0.2.3.1...
Preprocessing library split-0.2.3.1...
Preprocessing library split-0.2.3.1...
Haddock coverage:
  91% ( 62 / 68) in 'Data.List.Split.Internals'
  90% ( 45 / 50) in 'Data.List.Split'
Documentation created: dist/doc/html/split/index.html,
dist/doc/html/split/split.txt
Creating package registration file:
/tmp/pkgConf-split-0.2.32145174067468703135.1
Installing library in
/home/builder/hackage-server/build-cache/tmp-install/lib/x86_64-linux-ghc-8.0.1.20160521/split-0.2.3.1-IJKK4pOCYGKud0jZImZke
Registering split-0.2.3.1...
cabal: Leaving directory '/tmp/cabal-tmp-21829/split-0.2.3.1'
Installed split-0.2.3.1
Downloading libroman-3.0.0...
cabal: Entering directory '/tmp/cabal-tmp-21829/libroman-3.0.0'
Configuring libroman-3.0.0...
Building libroman-3.0.0...
Preprocessing library libroman-3.0.0...
[1 of 2] Compiling Data.Roman       ( src/Data/Roman.hs, dist/build/Data/Roman.o )

src/Data/Roman.hs:35:5: error:
    • Constraint ‘Roman r’ in the type of ‘fromRoman’
        constrains only the class type variables
      Use ConstrainedClassMethods to allow it
    • When checking the class method:
        fromRoman :: forall r.
                     Roman r =>
                     forall b. (Roman r, Integral b) => r -> b
      In the class declaration for ‘Roman’
cabal: Leaving directory '/tmp/cabal-tmp-21829/libroman-3.0.0'
Failed to install libroman-3.0.0
cabal: Error: some packages failed to install:
libroman-3.0.0 failed during the building phase. The exception was:
ExitFailure 1