Hi, This is not a pure MacPorts issue, as I'm doing the build manually and not through MacPorts, but I'm guessing that maybe you experienced this very same issue in recent LLVM versions, or that maybe you'll face it when you update to 6.0.1 (not released yet, but I'm trying release candidate #3, which might be the one tagged as final).
I first built it by using a previous 3.8.0 build I had on my Snow Leopard Mac. It went really smooth (although I didn't build lldb, openmp, nor compiler-rt), and I'm actually surprised I was able to build it without any patch at all (while I remember I had to apply some MacPorts patches in order to build 3.8.0). So, to my surprise, the compatibility of the LLVM source has increased with the years (I say "to my surprise" because usually compatibility gets worse with the years in recent open source projects). Said this, I'm now trying to self-host 6.0.1rc3. So I'm building 6.0.1rc3 with the 6.0.1rc3 build I got through 3.8.0 I started with libcxxabi, and I got an error I never saw before: /Users/cesar/LLVM/6.0.1rc3/libcxxabi/src/private_typeinfo.cpp:76:19: error: '~type_info' is unavailable: introduced in macOS 10.9 __shim_type_info::~__shim_type_info() ^ /Users/cesar/LLVM/6.0.1rc3/libcxx/include/typeinfo:122:13: note: '~type_info' has been explicitly marked unavailable here virtual ~type_info(); I raised my eyebrow, tried to build it with 3.8.0, and it built fine. Same flags, same everything. Even a diff on the included headers (got from invoking clang++ with '-H' argument) gets the very same results (except for the 3 headers that are inside the include dir of the installed LLVM, but they are identical except for minor differences in stdint.h which shouldn't be affecting here). Same flags, same included files, same everything... and 3.8.0 builds the file, while 6.0.1rc3 stops with the above error... Any clue on what could be happening here? Thanks!!