actually tests are there to be tested, just skip the variable assignment on windows
--- a/cmake_modules/compilerchecks.cmake Thu Jun 13 22:01:41 2013 +0200
+++ b/cmake_modules/compilerchecks.cmake Thu Jun 13 22:04:22 2013 +0200
@@ -21,9 +21,9 @@
set(CMAKE_SHARED_LIBRARY_CXX_FLAGS "${CMAKE_SHARED_LIBRARY_CXX_FLAGS} -fstack-protector-all -fstack-protector")
endif()
-#symbol visibility, not supported on Windows (so we error out to avoid spam)
-check_c_compiler_flag("-fvisibility=hidden -Werror" HAVE_VISIBILITY)
-if(HAVE_VISIBILITY)
+#symbol visibility, not supported on Windows
+check_c_compiler_flag("-fvisibility=hidden" HAVE_VISIBILITY)
+if(HAVE_VISIBILITY AND (NOT WIN32))
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fvisibility=hidden")
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fvisibility=hidden")
endif()