How to insert custom C++ compiler options into the conda-build flow?

I’d like to add the -Wno-c++11-narrowing compiler flag to the conda-build recipe for a particular project.
How do I do this?

Your best bet is to export the required environment variables in or bld.bat. Depending on the build system (CMake, autotools, etc), this might be CXXFLAGS or something else.

Thanks! It turns out this is doable directly in the meta.yaml file, but there is a pitfall that needs to be avoided. Please, see this SO post.