General notes on how the tooling works:
This setup uses conda for dependency management. Conda is able to pull the deps from a repository called conda-forge and setup an isolated build environment. Not quite as isolated as docker, but it is a good option for Mac and its what the FreeCAD CI system uses.
Once the dependencies are installed into a conda environment, then the
build uses the standard cmake configuration process to configure the build
and ninja to invoke the actual compilation against whatever host compiler
(gcc, clang, etc.) was installed by conda's cxx-compiler package for
that architecture.
All of this, and some sanity checks, are in a unified shell script. See below.
Run xcode-select --install and click through.
Refer to MiniConda Docs.
Run the ./build_unix_dev_conda.sh and go get coffee. Builds take
an hour+ on a 2012 Retina MacBook.
Output binaries will be in the ./build/bin/FreeCAD and
${CONDA_PREFIX}/bin/FreeCAD directories.
You can code/build/test using the cmake configuration folder ./build in
the standard way from within the freecad_dev conda environment.