Resolving dependencies...
Configuring QuickCheck-1.2.0.1...
Building QuickCheck-1.2.0.1...
Preprocessing library QuickCheck-1.2.0.1...
[1 of 8] Compiling Test.QuickCheck  ( Test/QuickCheck.hs, dist/build/Test/QuickCheck.o )
[2 of 8] Compiling Test.QuickCheck.Batch ( Test/QuickCheck/Batch.hs, dist/build/Test/QuickCheck/Batch.o )
[3 of 8] Compiling Test.QuickCheck.Utils ( Test/QuickCheck/Utils.hs, dist/build/Test/QuickCheck/Utils.o )
[4 of 8] Compiling Test.QuickCheck.Poly ( Test/QuickCheck/Poly.hs, dist/build/Test/QuickCheck/Poly.o )
[5 of 8] Compiling Debug.QuickCheck.Poly ( Debug/QuickCheck/Poly.hs, dist/build/Debug/QuickCheck/Poly.o )
[6 of 8] Compiling Debug.QuickCheck.Utils ( Debug/QuickCheck/Utils.hs, dist/build/Debug/QuickCheck/Utils.o )
[7 of 8] Compiling Debug.QuickCheck ( Debug/QuickCheck.hs, dist/build/Debug/QuickCheck.o )
[8 of 8] Compiling Debug.QuickCheck.Batch ( Debug/QuickCheck/Batch.hs, dist/build/Debug/QuickCheck/Batch.o )
In-place registering QuickCheck-1.2.0.1...
Running Haddock for QuickCheck-1.2.0.1...
Running hscolour for QuickCheck-1.2.0.1...
Preprocessing library QuickCheck-1.2.0.1...
Preprocessing library QuickCheck-1.2.0.1...
Haddock coverage:
   3% (  1 / 33) in 'Test.QuickCheck'
  50% (  4 /  8) in 'Test.QuickCheck.Batch'
  17% (  1 /  6) in 'Test.QuickCheck.Utils'
  14% (  1 /  7) in 'Test.QuickCheck.Poly'
 100% (  2 /  2) in 'Debug.QuickCheck.Poly'
 100% (  2 /  2) in 'Debug.QuickCheck.Utils'
 100% (  2 /  2) in 'Debug.QuickCheck.Batch'
 100% (  2 /  2) in 'Debug.QuickCheck'
Warning: Test.QuickCheck.Poly: could not find link destinations for:
    Test.QuickCheck.Poly.Poly Test.QuickCheck.Poly.ALPHA_ Test.QuickCheck.Poly.BETA_ Test.QuickCheck.Poly.GAMMA_ Test.QuickCheck.Poly.OrdALPHA_ Test.QuickCheck.Poly.OrdBETA_ Test.QuickCheck.Poly.OrdGAMMA_
Documentation created: dist/doc/html/QuickCheck/index.html,
dist/doc/html/QuickCheck/QuickCheck.txt
Installing library in
/srv/hackage/var/build/tmp-install/lib/x86_64-linux-ghc-7.6.3/QuickCheck-1.2.0.1
Registering QuickCheck-1.2.0.1...
Installed QuickCheck-1.2.0.1
Downloading HCodecs-0.4.1...
Configuring HCodecs-0.4.1...
Building HCodecs-0.4.1...
Preprocessing library HCodecs-0.4.1...
[1 of 7] Compiling Internal.Arbitrary ( src/Internal/Arbitrary.hs, dist/build/Internal/Arbitrary.o )
[2 of 7] Compiling Internal.ByteString.Builder ( src/Internal/ByteString/Builder.hs, dist/build/Internal/ByteString/Builder.o )

src/Internal/ByteString/Builder.hs:159:37:
    Ambiguous occurrence `unsafePerformIO'
    It could refer to either `Foreign.unsafePerformIO',
                             imported from `Foreign' at src/Internal/ByteString/Builder.hs:65:1-14
                          or `System.IO.Unsafe.unsafePerformIO',
                             imported from `System.IO.Unsafe' at src/Internal/ByteString/Builder.hs:66:26-40
                             (and originally defined in `GHC.IO')
Failed to install HCodecs-0.4.1
cabal: Error: some packages failed to install:
HCodecs-0.4.1 failed during the building phase. The exception was:
ExitFailure 1