Questions about the firmware

I downloaded the firmware at GITHUB. Why BOOTLOAD can make make a success directly, but there are many errors and problems when making the firmware make? For example, now. It prompts me: zubax_chibios// *** USE_PROCESS_STACKSIZE is not defined. Stop.
When I open, this is the case.
35 $(error USE_PROCESS_STACKSIZE is not defined)
36 endif
I don’t know where USE_PROCESS_STACKSIZE should be defined.
Is it a problem with my system or where is the problem.

Remove the archive you have downloaded from GitHub and clone the repository properly instead:

git clone --recursive