Fix GHCJS 7.10

pkgs/development/compilers/ghcjs/default.nix

@@ -2,5 +2,4 @@
 
 bootPkgs.callPackage ./base.nix {
   inherit bootPkgs cabal-install;
-  broken = true;  # https://hydra.nixos.org/build/70552553
 }

pkgs/development/haskell-modules/configuration-ghc-7.10.x.nix

@@ -219,4 +219,15 @@ self: super: {
   chr-pretty = doJailbreak super.chr-pretty;
   chr-parse = doJailbreak super.chr-parse;
 
+  # The autogenerated Nix expressions don't take into
+  # account `if impl(ghc >= x.y)`, which is a common method to depend
+  # on `semigroups` or `fail` when building with GHC < 8.0.
+  system-filepath = addBuildDepend super.system-filepath self.semigroups;
+  haskell-src-exts = addBuildDepend super.haskell-src-exts self.semigroups;
+  free = addBuildDepend super.free self.fail;
+
+  # Newer versions don't build without base-4.9
+  resourcet = self.resourcet_1_1_11;
+  conduit = self.conduit_1_2_13_1;
+
 }

pkgs/development/haskell-modules/configuration-ghcjs.nix

@@ -53,19 +53,6 @@ self: super:
   terminfo = self.terminfo_0_4_0_2;
   xhtml = self.xhtml_3000_2_1;
 
-  # Cabal isn't part of the stage1 packages which form the default package-db
-  # that GHCJS provides.
-  # Almost all packages require Cabal to build their Setup.hs,
-  # but usually they don't declare it explicitly as they don't need to for normal GHC.
-  # To account for that we add Cabal by default.
-  mkDerivation = args: super.mkDerivation (args // {
-    setupHaskellDepends = (args.setupHaskellDepends or []) ++
-      (if args.pname == "Cabal" then [ ]
-      # Break the dependency cycle between Cabal and hscolour
-      else if args.pname == "hscolour" then [ (dontHyperlinkSource self.Cabal) ]
-      else [ self.Cabal ]);
-  });
-
 ## OTHER PACKAGES
 
   # haddock throws the error: No input file(s).