24:59.79 ld.lld: error: ../../../../../x86_64-unknown-linux-gnu/release/libbuiltins_static.a(builtins_static-446ac020593e99f6.builtins_static.badaedcd76fe810c-cgu.0.rcgu.o): Invalid attribute group entry (Producer: 'LLVM19.1.2' Reader: 'LLVM 18.1.8') 24:59.80 x86_64-pc-linux-gnu-clang++-18: error: linker command failed with exit code 1 (use -v to see invocation) Reproducible: Always Constant struggles with clang-llvm version vs rust vs firefox is _exhausting_. I know it is a topic, that upstream uses clang, but in the mean time the stuff compiles just fine with USE="-clang" without all the hassles.
I guess you have two rusts installed? If it's constant struggle, you should package.mask the rust you're not using locally (source or -bin). But maybe this helps for now bug 941878 until someone slots rust properly.