opencv: Use multiple outputs and prevent runtime dependency on GCC

pkgs/development/libraries/opencv/default.nix

@@ -28,6 +28,14 @@ stdenv.mkDerivation rec {
     sha256 = "1k29rxlvrhgc5hadg2nc50wa3d2ls9ndp373257p756a0aividxh";
   };
 
+  patches =
+    [ # Don't include a copy of the CMake status output in the
+      # build. This causes a runtime dependency on GCC.
+      ./no-build-info.patch
+    ];
+
+  outputs = [ "out" "dev" ];
+
   buildInputs =
        [ zlib ]
     ++ lib.optional enablePython pythonPackages.python

pkgs/development/libraries/opencv/no-build-info.patch

@@ -0,0 +1,14 @@
+diff -ru -x '*~' opencv-2.4.13-orig/modules/core/src/system.cpp opencv-2.4.13/modules/core/src/system.cpp
+--- opencv-2.4.13-orig/modules/core/src/system.cpp	1970-01-01 01:00:01.000000000 +0100
++++ opencv-2.4.13/modules/core/src/system.cpp	2016-10-02 18:44:53.674181762 +0200
+@@ -442,9 +442,7 @@
+ 
+ const std::string& getBuildInformation()
+ {
+-    static std::string build_info =
+-#include "version_string.inc"
+-    ;
++    static std::string build_info = "(build info elided)";
+     return build_info;
+ }
+