Building VTK 8.1 against 10.13 SDK results in linker errors when trying to use resulting libraries on older SDK
tl;dr: VTK needs aa9f3a82b2c4f0fa1016908c58a375eba185f2d9 from KWSys.
Otherwise, if you build VTK against 10.13 SDK, then try to use the resulting libraries in an app that uses the 10.12 SDK you get this link error:
Undefined symbols for architecture x86_64: "_utimensat", referenced from: vtksys::SystemTools::Touch(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, bool) in libvtksys.a(SystemTools.cxx.o)
If SystemTools::Touch() is invoked at runtime, it'll likely crash.
This is worth putting in VTK 8.1.1
@brad.king : could you pretty please do the git magic to get newer KWSys (either just that commit or master, I dunno) into the VTK 8.1 branch?