usr/lib64/chromium-browser/chrome contain writable and executable sections. Files with such sections will not work properly (or at all!) on some architectures/operating systems.
can you attach the full build log?
The portage elog was configured to echo only, reconfigured to also save, plus, elog classes didn't include qa, that's why it was only saved during building, but not retained afterwards.
From the out/Release directory: > --- --- RWX ./chrome > !WX --- --- ./obj/third_party/crashpad/crashpad/util/util/capture_context_linux.o > !WX --- --- ./obj/third_party/crashpad/crashpad/client/client/crashpad_info_note.o > !WX --- --- ./obj/third_party/boringssl/boringssl_asm/x86_64-mont5.o > !WX --- --- ./obj/third_party/boringssl/boringssl_asm/x86_64-mont.o > !WX --- --- ./obj/third_party/boringssl/boringssl_asm/sha512-x86_64.o > !WX --- --- ./obj/third_party/boringssl/boringssl_asm/vpaes-x86_64.o > !WX --- --- ./obj/third_party/boringssl/boringssl_asm/sha256-x86_64.o > !WX --- --- ./obj/third_party/boringssl/boringssl_asm/sha1-x86_64.o > !WX --- --- ./obj/third_party/boringssl/boringssl_asm/rsaz-avx2.o > !WX --- --- ./obj/third_party/boringssl/boringssl_asm/rdrand-x86_64.o > !WX --- --- ./obj/third_party/boringssl/boringssl_asm/p256-x86_64-asm.o > !WX --- --- ./obj/third_party/boringssl/boringssl_asm/md5-x86_64.o > !WX --- --- ./obj/third_party/boringssl/boringssl_asm/ghash-x86_64.o > !WX --- --- ./obj/third_party/boringssl/boringssl_asm/bsaes-x86_64.o > !WX --- --- ./obj/third_party/boringssl/boringssl_asm/aes-x86_64.o > !WX --- --- ./obj/third_party/boringssl/boringssl_asm/aesni-x86_64.o > !WX --- --- ./obj/third_party/boringssl/boringssl_asm/aesni-gcm-x86_64.o > !WX --- --- ./obj/third_party/boringssl/boringssl_asm/chacha20_poly1305_x86_64.o > !WX --- --- ./obj/third_party/boringssl/boringssl_asm/aes128gcmsiv-x86_64.o > !WX --- --- ./obj/third_party/boringssl/boringssl_asm/chacha-x86_64.o > !WX --- --- ./obj/third_party/blink/renderer/platform/heap/asm/asm/SaveRegisters_x86.o
I was experimenting with some flags, and accidental discovered that adding sys-devel/lld as a new dependency and with these flags (is_cfi=true, use_gold=true and use_lld=true) fixed the issue for me. Probably the last 2 flags are already enabled by default?! It seems to resolves #641556 too. But I'm not so sure, as I've only tested 67.0.3396.62 with clang-6.
Created attachment 534902 [details, diff] add sys-devel/lld as dependency, correct some flags/comments
Using lld probably just masks the problem here.