To build the Linux Kernel with link-time optimization, it must be built with clang. This request entails the addition of a USE flag that selects clang for building the Kernel, as opposed to GCC. Thank you for considering.
Why not just use package.env and/or /etc/kernel/config.d? https://wiki.gentoo.org/wiki/Project:Distribution_Kernel#Using_.2Fetc.2Fkernel.2Fconfig.d
(In reply to Sam James from comment #1) > Why not just use package.env and/or /etc/kernel/config.d? > > https://wiki.gentoo.org/wiki/Project:Distribution_Kernel#Using_.2Fetc. > 2Fkernel.2Fconfig.d package.env seems to actually be working. Not the solution I'd prefer, but I'll mark this bug as resolved. Thank you.