haskell-testpack: patch to support recent versions of QuickCheck

pkgs/development/libraries/haskell/testpack/default.nix

@@ -5,6 +5,7 @@ cabal.mkDerivation (self: {
   version = "2.1.2";
   sha256 = "12dhl8svy0wmdwlvkp0p0j6wr6vgv4hrjcpdv48kc5rcwjvh8xif";
   buildDepends = [ HUnit mtl QuickCheck random ];
+  patches = [ ./support-recent-quickcheck.patch ];
   meta = {
     homepage = "http://hackage.haskell.org/cgi-bin/hackage-scripts/package/testpack";
     description = "Test Utililty Pack for HUnit and QuickCheck";

pkgs/development/libraries/haskell/testpack/support-recent-quickcheck.patch

@@ -0,0 +1,22 @@
+diff --git a/src/Test/HUnit/Tools.hs b/src/Test/HUnit/Tools.hs
+index 01fac30..0de5526 100644
+--- a/src/Test/HUnit/Tools.hs
++++ b/src/Test/HUnit/Tools.hs
+@@ -128,7 +128,7 @@ Often used like this:
+ >        q "Integer -> Int (safe bounds)" prop_integer_to_int_pass]
+ -}
+ qc2hu :: QC.Testable a => Int -> String -> a -> HU.Test
+-qc2hu maxTest = qccheck (stdArgs {maxSuccess = maxTest, maxDiscard = 20000})
++qc2hu maxTest = qccheck (stdArgs {maxSuccess = maxTest})
+ 
+ {- | Run verbose tests.  Example:
+ 
+@@ -174,7 +174,7 @@ localquickCheckWithResult args p =
+               Just (rnd,_) -> return rnd
+      test MkState{ terminal          = tm
+                  , maxSuccessTests   = maxSuccess args
+-                 , maxDiscardedTests = maxDiscard args
++                 , maxDiscardedTests = 20000
+                  , computeSize       = case replay args of
+                                          Nothing    -> \n d -> (n * maxSize args)
+                                                          `div` maxSuccess args

pkgs/top-level/haskell-packages.nix

@@ -1607,9 +1607,7 @@ let result = let callPackage = x : y : modifyPrio (newScope result.final x y);
 
   testFrameworkThPrime = callPackage ../development/libraries/haskell/test-framework-th-prime {};
 
-  testpack = callPackage ../development/libraries/haskell/testpack {
-    QuickCheck = self.QuickCheck_2_4_2;
-  };
+  testpack = callPackage ../development/libraries/haskell/testpack {};
 
   texmath = callPackage ../development/libraries/haskell/texmath {};