Add lambdabot wrapper and mueval wrapper to make lambdabot run out of the box

pkgs/development/libraries/haskell/lambdabot/wrapper.nix

@@ -0,0 +1,19 @@
+{ stdenv, lambdabot, mueval, makeWrapper }:
+
+stdenv.mkDerivation {
+  name = "lambdabot-wrapper";
+
+  buildInputs = [ makeWrapper ];
+
+  buildCommand = ''
+    makeWrapper "${lambdabot}/bin/lambdabot" "$out/bin/lambdabot" \
+      --prefix PATH : "${mueval}/bin"
+  '';
+
+  preferLocalBuild = true;
+
+  meta = {
+    description = lambdabot.meta.description;
+  };
+}
+

pkgs/development/libraries/haskell/mueval/wrapper.nix

@@ -0,0 +1,33 @@
+{ stdenv, mueval, makeWrapper, ghc
+, show, simpleReflect, mtl, random, QuickCheck
+, additionalPackages ? [] }:
+
+stdenv.mkDerivation {
+  name = "mueval-wrapper";
+
+  buildInputs = [ makeWrapper show simpleReflect mtl random QuickCheck ]
+    ++ additionalPackages;
+
+  ghcVersion = ghc.version;
+
+  buildCommand = ''
+    PKGPATH=""
+    for p in $nativePkgs; do
+      for i in "$p/lib/ghc-$ghcVersion/package.conf.d/"*.installedconf; do
+        PKGPATH=$PKGPATH''${PKGPATH:+:}$i
+      done
+    done
+
+    makeWrapper "${mueval}/bin/mueval" "$out/bin/mueval" \
+      --prefix PATH : "${mueval}/bin" \
+      --prefix GHC_PACKAGE_PATH : "$PKGPATH" \
+      --set GHC_PACKAGE_PATH "\$GHC_PACKAGE_PATH:" # always end with : to include base packages
+  '';
+
+  preferLocalBuild = true;
+
+  meta = {
+    description = mueval.meta.description;
+  };
+}
+