Resolving dependencies...
Configuring old-locale-1.0.0.7...
Configuring mtl-2.2.1...
Building old-locale-1.0.0.7...
Building mtl-2.2.1...
Configuring stm-2.4.4.1...
Installed old-locale-1.0.0.7
Building stm-2.4.4.1...
Configuring random-1.1...
Installed mtl-2.2.1
Configuring syb-0.6...
Installed stm-2.4.4.1
Building random-1.1...
Building syb-0.6...
Configuring text-1.2.2.1...
Installed random-1.1
Building text-1.2.2.1...
Configuring queue-0.1.2...
Installed syb-0.6
Building queue-0.1.2...
Installed queue-0.1.2
Installed text-1.2.2.1
Configuring hashable-1.2.4.0...
Configuring parsec-3.1.11...
Building hashable-1.2.4.0...
Building parsec-3.1.11...
Installed hashable-1.2.4.0
Configuring OptDir-0.0.3...
Building OptDir-0.0.3...
Installed OptDir-0.0.3
Installed parsec-3.1.11
Configuring parse-dimacs-1.3...
Building parse-dimacs-1.3...
Installed parse-dimacs-1.3
Downloading toysolver-0.0.2...
Configuring toysolver-0.0.2...
Building toysolver-0.0.2...
Failed to install toysolver-0.0.2
Build log ( /home/builder/.cabal/logs/toysolver-0.0.2.log ):
cabal: Entering directory '/tmp/cabal-tmp-14604/toysolver-0.0.2'
Configuring toysolver-0.0.2...
Building toysolver-0.0.2...
Preprocessing executable 'toysolver' for toysolver-0.0.2...
[ 1 of 28] Compiling Version          ( src/Version.hs, dist/build/toysolver/toysolver-tmp/Version.o )

src/Version.hs:11:5: warning: [-Wdeprecations]
    In the use of ‘versionTags’ (imported from Data.Version):
    Deprecated: "See GHC ticket #2496"
[ 2 of 28] Compiling Util             ( src/Util.hs, dist/build/toysolver/toysolver-tmp/Util.o )
[ 3 of 28] Compiling Text.PBFile      ( src/Text/PBFile.hs, dist/build/toysolver/toysolver-tmp/Text/PBFile.o )
[ 4 of 28] Compiling Text.LPFile      ( src/Text/LPFile.hs, dist/build/toysolver/toysolver-tmp/Text/LPFile.o )

src/Text/LPFile.hs:660:5: error:
    • Non type-variable argument in the constraint: MonadWriter ShowS m
      (Use FlexibleContexts to permit this)
    • When checking the inferred type
        go :: forall (m :: * -> *).
              MonadWriter ShowS m =>
              [String] -> Int -> m ()
      In an equation for ‘fill’:
          fill width xs
            = go xs 0
            where
                go [] _ = return ()
                go (x : xs) 0 = tell (showString x) >> go xs (length x)
                go (x : xs) w
                  = if w + 1 + length x <= width then
                        tell (showChar ' ' . showString x) >> go xs (w + 1 + length x)
                    else
                        tell (showChar '\n') >> go (x : xs) 0
cabal: Leaving directory '/tmp/cabal-tmp-14604/toysolver-0.0.2'
cabal: Error: some packages failed to install:
toysolver-0.0.2 failed during the building phase. The exception was:
ExitFailure 1