Compilation FAILS #define ARDUINO?

I guess this is due to the recent "improvements" towards Arduino compatibility
See here

You could try adding

#pragma PARTICLE_NO_ARDUINO_COMPATIBILITY

or you target 0.6.0 till the issue gets addressed.

But I'm not sure. We can ping @BDub and @jvanier about this.

BTW, this SDFat library should be better to use now as it has some major improvements built in.