c2ffi compilation fails on OpenBSD

[/home/dan] $ uname -a
OpenBSD lsd3 6.0 GENERIC.MP#0 amd64
[/home/dan] $ cmake ..
-- The C compiler identification is GNU 4.2.1
-- The CXX compiler identification is GNU 4.2.1
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
CMake Error at CMakeLists.txt:15 (find_package):
  Could not find a configuration file for package "LLVM" that is compatible
  with requested version "3.7".

  The following configuration files were considered but not accepted:

    /usr/local/share/llvm/cmake/LLVMConfig.cmake, version: 3.8.0



-- Configuring incomplete, errors occurred!
See also "/home/dan/src/c2ffi/build/CMakeFiles/CMakeOutput.log".