@@ -135,6 +135,7 @@ iiBuildTools InstallInfo { iiPackageDB = PackageDB m, iiPackages = packages } =
135135 -- FIXME possible improvement: track the dependencies between the build
136136 -- tools themselves, and install them in the correct order.
137137 map unPackageName
138+ $ filter (flip Set.notMember coreTools)
138139 $ filter (flip Map.member m)
139140 $ Set.toList
140141 $ Set.unions
@@ -145,3 +146,7 @@ iiBuildTools InstallInfo { iiPackageDB = PackageDB m, iiPackages = packages } =
145146 unPackageName (PackageName pn) = pn
146147 isSelected name _ = name `Set.member` selected
147148 selected = Set.fromList $ Map.keys packages
149+
150+ -- Build tools shipped with GHC which we should not attempt to build
151+ -- ourselves.
152+ coreTools = Set.fromList $ map PackageName $ words "hsc2hs"