Compiling Kernel Fails with certificate error

I’m trying to build the kernel from here: https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git/

and it fails with certificate error. I have run sudo make menuconfig, and then have edited the resulting .config file with nano to comment out “CONFIG_SYSTEM_TRUSTED_KEYS”. It still fails with certificate error. The build process does ask questions about keys, and I think this is where the .config file is getting updated and resulting in the failure. If I edit the .config file afterwards “CONFIG_SYSTEM_TRUSTED_KEYS” is no longer commented out. Can anyone point out where I’m going wrong?