This is an auto-filled bug because sys-kernel/linux-docs calls cc directly.
The issue was originally discovered on arm64, but it may be reproducible on other arches as well.
If you think that a different summary clarifies the issue better, feel free to change it.
Attached build log and emerge --info.
If you think it doesn't make sense fix these type of issues, I'd like to point out that won't be possible use a different CC implementation (like clang) by setting the CC variable. So this issue has been reproduced by setting the CC variable to aarch64-unknown-linux-gnu-gcc and by removing the /usr/bin/cc - /usr/bin/gcc binaries.
Created attachment 636824 [details]
build log and emerge --info
No compiler is used here. That warning can be ignored.
Looks like the problem is that fc-list is missing.
That needs to be added as a dependency.
I removed the gcc binary and built linux-docs.