Today I spend quite a while figuring out why I could install base<4 while using flag base4. The reason was that I forgot to add the label build-depends: when patching. If those lines are ignored shouldn't there be a warning? Marc Weber name:QuickCheck version:1.2.0.0 license:BSD3 license-file:LICENSE author:Koen Classen and John Hughes maintainer:libraries@haskell.org category:Testing homepage:http://www.math.chalmers.se/~rjmh/QuickCheck/ synopsis:Automatic testing of Haskell programs description: A library for testing Haskell programs automatically. The programmer provides a specification of the program, in the form of properties which functions should satisfy, and QuickCheck then tests that the properties hold in a large number of randomly generated cases. Specifications are expressed in Haskell, using combinators defined in the QuickCheck library. QuickCheck provides combinators to define properties, observe the distribution of test data, and define test data generators. build-type: Simple cabal-version: >=1.2 flag split-base flag base4 library exposed-modules: Debug.QuickCheck.Batch, Debug.QuickCheck.Poly, Debug.QuickCheck.Utils, Debug.QuickCheck, Test.QuickCheck.Batch, Test.QuickCheck.Poly, Test.QuickCheck.Utils, Test.QuickCheck if flag(split-base) build-depends:base >= 3 && < 5, random if flag(base4) base >= 4 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ << cpp-options: -DBASE4 else base < 4 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ << else build-depends:base < 3 extensions:CPP