uboot: (firmwareOdroidC2/C4) don't invoke patch tool, use patches = [] instead

https://github.com/NixOS/nixpkgs/blob/master/pkgs/stdenv/generic/setup.sh#L948
this can do it nicely.

Signed-off-by: Anton Arapov <anton@deadbeef.mx>

pkgs/applications/misc/gitit/default.nix

@@ -0,0 +1,61 @@
+{ lib, haskellPackages, haskell, removeReferencesTo
+# “Plugins” are a fancy way of saying gitit will invoke
+# GHC at *runtime*, which in turn makes it pull GHC
+# into its runtime closure. Only enable if you really need
+# that feature. But if you do you’ll want to use gitit
+# as a library anyway.
+, pluginSupport ? false
+}:
+
+# this is similar to what we do with the pandoc executable
+
+let
+  plain = haskellPackages.gitit;
+  plugins =
+    if pluginSupport
+    then plain
+    else haskell.lib.compose.disableCabalFlag "plugins" plain;
+  static = haskell.lib.compose.justStaticExecutables plugins;
+
+in
+  (haskell.lib.compose.overrideCabal (drv: {
+    buildTools = (drv.buildTools or []) ++ [ removeReferencesTo ];
+  }) static).overrideAttrs (drv: {
+
+    # These libraries are still referenced, because they generate
+    # a `Paths_*` module for figuring out their version.
+    # The `Paths_*` module is generated by Cabal, and contains the
+    # version, but also paths to e.g. the data directories, which
+    # lead to a transitive runtime dependency on the whole GHC distribution.
+    # This should ideally be fixed in haskellPackages (or even Cabal),
+    # but a minimal gitit is important enough to patch it manually.
+    disallowedReferences = [
+      haskellPackages.pandoc-types
+      haskellPackages.HTTP
+      haskellPackages.pandoc
+      haskellPackages.happstack-server
+      haskellPackages.filestore
+    ];
+    postInstall = ''
+      remove-references-to \
+        -t ${haskellPackages.pandoc-types} \
+        $out/bin/gitit
+      remove-references-to \
+        -t ${haskellPackages.HTTP} \
+        $out/bin/gitit
+      remove-references-to \
+        -t ${haskellPackages.pandoc} \
+        $out/bin/gitit
+      remove-references-to \
+        -t ${haskellPackages.happstack-server} \
+        $out/bin/gitit
+      remove-references-to \
+        -t ${haskellPackages.filestore} \
+        $out/bin/gitit
+    '';
+
+    meta = drv.meta // {
+      maintainers = drv.meta.maintainers or []
+        ++ [ lib.maintainers.Profpatsch ];
+    };
+  })