For past dozen days I couldn't update my system due to sys-libs/compiler-rt-sanitizers-9.0.1 not emerging, but when I emerge it by itself it does not complain and I didn't know what to make of it.

Thanks to krish 's spot-on hypothesis, I was able to leave that outdated llvm version once I removed "opencl" flags from my package.use. Too bad, as I'll most likely need fully-working openCL stack this summer.

Reproduction steps:

1. emerge firefox. This has been fixed by removing firefox, since it was outdated. Use firefox-bin instead
2. set media-libs/mesa to have opencl enabled. Now emerge mesa. This is pulling in the older compiler-rt-sanitizers via libclc. This now appears fixed but needs more testing – on my system with the new libclc, it is pulling in clang-11 and compiler-rt-sanitizers-11.
3. add any more vectors for reproduction here as they are found.