Seems like a nothingburger? Mostly a spammy GitHub thread of people not reading the rest of the responses.
> Works if you supply the correct include path(s)
> Can confirm, works fine:
> You could arguably fault ccc's driver for not specifying the include path to find the native C library on this system.
> (I followed the instructions in the BUILDING_LINUX.txt file in the repo and got the kernel built for RISC-V. You can find the build I made here if someone is just interested in the binaries)