cgal: add patch so include files can be found by dependent packages

pkgs/development/libraries/CGAL/cgal_path.patch

@@ -0,0 +1,15 @@
+--- Installation/cmake/modules/CGALConfig_install.cmake.in.original	2019-07-10 10:39:12.377022659 -0700
++++ Installation/cmake/modules/CGALConfig_install.cmake.in	2019-07-10 10:47:24.310154928 -0700
+@@ -45,9 +45,9 @@
+ set(CGAL_SHARED_LINKER_FLAGS_DEBUG_INIT   "@CMAKE_SHARED_LINKER_FLAGS_DEBUG@" )
+ set(CGAL_BUILD_TYPE_INIT                  "@CMAKE_BUILD_TYPE@" )
+
+-set(CGAL_INCLUDE_DIRS  "${CGAL_INSTALL_PREFIX}/@CGAL_INSTALL_INC_DIR@" )
+-set(CGAL_MODULES_DIR   "${CGAL_INSTALL_PREFIX}/@CGAL_INSTALL_CMAKE_DIR@" )
+-set(CGAL_LIBRARIES_DIR "${CGAL_INSTALL_PREFIX}/@CGAL_INSTALL_LIB_DIR@" )
++set(CGAL_INCLUDE_DIRS  "@CGAL_INSTALL_INC_DIR@" )
++set(CGAL_MODULES_DIR   "@CGAL_INSTALL_CMAKE_DIR@" )
++set(CGAL_LIBRARIES_DIR "@CGAL_INSTALL_LIB_DIR@" )
+
+ # If CGAL_ImageIO is built, tell if it was linked with Zlib.
+ set(CGAL_ImageIO_USE_ZLIB                 "@CGAL_ImageIO_USE_ZLIB@" )

pkgs/development/libraries/CGAL/default.nix

@@ -1,8 +1,14 @@
-{ stdenv, fetchFromGitHub, cmake, boost, gmp, mpfr }:
+{ stdenv
+, fetchFromGitHub
+, cmake
+, boost
+, gmp
+, mpfr
+}:
 
 stdenv.mkDerivation rec {
+  pname = "cgal";
   version = "5.0.2";
-  name = "cgal-" + version;
 
   src = fetchFromGitHub {
     owner = "CGAL";
@@ -16,6 +22,8 @@ stdenv.mkDerivation rec {
   buildInputs = [ boost gmp mpfr ];
   nativeBuildInputs = [ cmake ];
 
+  patches = [ ./cgal_path.patch ];
+
   doCheck = false;
 
   meta = with stdenv.lib; {