libkdtree | Tree model implemented by C

Here are a few hints:

• Use gcc instead of llvm or clang for painless openmp-support on macOS. Note that apple's default gcc is just an alias for Apple clang as you'll see with gcc --version. You can install the real gcc with homebrew: brew install gcc.

• Then use export CC='gcc-10' (the newest version should be gcc 10.x) inside the same terminal window to use homebrew's gcc temporarily as your C compiler.

• There's no need to set CXXFLAGS or CFLAGS. The required flags are set by distutils/setuptools inside the setup.py.

• You won't be able to compile dmc_cuda_module on macOS 10.14.6. The latest macOS version nvidia offers cuda drivers for is 10.13.6. So you might uncomment this part of the setup.py and hope for the best you don't need this module...

• Some of the Extensions inside the setup.py aren't including the numpy headers while using the numpy C-API. On macOS it's necessary to include the numpy headers for each Extension, see this comment. So you have to add include_dirs=[numpy_include_dir] to those Extensions.

• Edit: As discussed in the chat: The error was due to the conda env ignoring the CC variable. After installing python+pip via homebrew and the required python packages via pip, this answer's steps worked for the OP.

All in all, here's a setup.py that worked for me (macOS 10.5.7, gcc-10):