Now, it gets past the error about nasm, but the build fails with this error: Initializing workspace
I then tried to build the EmulatorPkg as recommended by the documentation I did have to install nasm via Homebrew to get past an error message support Apple's shipping nasm not supporting a required format. I followed the instructions exactly as described here, up to building UnixPkg. I am trying to build the EFI Development Kit (EDK2) on OS X Yosemite.