Electron 4 MacOS build error

[pfrazee]

I have to manually rebuild my native modules in my Electron app, and in Electron v4 this module started to break with:

clang: error: invalid deployment target for -stdlib=libc++ (requires OS X 10.7 or later)

After some googling & trial/error, the solution I concocted was to modify node-spellchecker's binding.gyp to include

           'OTHER_CFLAGS': [
             '-mmacosx-version-min=10.10'
           ]

That's inside the xcode_settings of the target_defaults section. I also had to set env vars:

export CXXFLAGS="-mmacosx-version-min=10.10"
export LDFLAGS="-mmacosx-version-min=10.10"

Without the binding.gyp change, the initial compile would fail. Without the env vars, the link step would fail.

I can do the env vars in my build script but the binding.gyp change has to be in the module, afaict. I can use a fork for now, so no pressure to fix in the main repo, but hopefully you know the build systems well enough to address this for everyone! (I unfortunately don't).