Warning message when building blender

I have no idea if this the right forum, but here we go:

Do anyone know what this means? " cl : Command line warning D9002: ignoring unknown option ‘/utf-8’ [C:\blender-git\build_windows_Release_x64_vc12_Release\intern\cycles\render\cycles_render.vcxproj]" the last part " cycles_render.vcxproj" is different on each warning. It is a warning not an error, but maybe this can cause problem later.