Do not enable CUDA under mingw.

src/CMakeLists.txt

@@ -50,10 +50,16 @@ ENDIF(CG_FOUND)
 # CUDA
 FIND_PACKAGE(CUDA)
 IF(CUDA_FOUND)
-	SET(HAVE_CUDA ${CUDA_FOUND} CACHE BOOL "Set to TRUE if CUDA is found, FALSE otherwise")
-	MESSAGE(STATUS "Looking for CUDA - found")
+    IF(MINGW)
+        MESSAGE(STATUS "Looking for CUDA - not supported on MinGW")
+        UNSET(CUDA_FOUND)
+    ENDIF(MINGW)
+    IF(CUDA_FOUND)
+        SET(HAVE_CUDA ${CUDA_FOUND} CACHE BOOL "Set to TRUE if CUDA is found, FALSE otherwise")
+        MESSAGE(STATUS "Looking for CUDA - found")
+    ENDIF(CUDA_FOUND)
 ELSE(CUDA_FOUND)
-	MESSAGE(STATUS "Looking for CUDA - not found")
+    MESSAGE(STATUS "Looking for CUDA - not found")
 ENDIF(CUDA_FOUND)
 
 # Maya