+handle cmake & ccache
+http://stackoverflow.com/questions/1815688/how-to-use-ccache-with-cmake
+
+--- hhvm-HHVM-3.2.0/CMake/HPHPCompiler.cmake~ 2014-07-18 03:12:10.000000000 +0300
++++ hhvm-HHVM-3.2.0/CMake/HPHPCompiler.cmake 2014-08-10 23:40:37.972367254 +0300
+@@ -22,7 +22,7 @@
+ set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-O2 -g")
+ # using GCC
+ elseif ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
+- execute_process(COMMAND ${CMAKE_CXX_COMPILER} -dumpversion OUTPUT_VARIABLE GCC_VERSION)
++ execute_process(COMMAND ${CMAKE_CXX_COMPILER} ${CMAKE_CXX_COMPILER_ARG1} -dumpversion OUTPUT_VARIABLE GCC_VERSION)
+ set(GNUCC49_OPT "")
+ if (NOT (GCC_VERSION VERSION_GREATER 4.8 OR GCC_VERSION VERSION_EQUAL 4.8))
+ message(FATAL_ERROR "${PROJECT_NAME} requires g++ 4.8 or greater.")