Hello, Attempting to build jhc (the make install), I get: [ 8 of 166] Compiling Util.ArbitraryInstances ( Util/ArbitraryInstances.hs, Util/ArbitraryInstances.o ) Util/ArbitraryInstances.hs:7:0: Duplicate instance declarations: instance [overlap ok] (Arbitrary a) => Arbitrary (Maybe a) -- Defined at Util/ArbitraryInstances.hs:7:0 instance (Arbitrary a) => Arbitrary (Maybe a) -- Defined in Test.QuickCheck Util/ArbitraryInstances.hs:14:0: Duplicate instance declarations: instance [overlap ok] (Arbitrary a, Arbitrary b) => Arbitrary (Either a b) -- Defined at Util/ArbitraryInstances.hs:14:0 instance (Arbitrary a, Arbitrary b) => Arbitrary (Either a b) -- Defined in Test.QuickCheck make: *** [jhc] Error 1 tn@linux:~> This happens on a PPC Mac OS X 10.4. GHC is ghc 6.6 branch from February 21st 2007. Help to proceed from here would be most appreciated. Thanks and the best regards Thorkil