apparently having some LTO’d static libraries can cause issues

Yeah, I think I’ve had that problem once or twice. I think I found the culprits by disabling all build flags for libraries that seemed related, rebuilding them, running emerge @preserved-rebuild and then repeating the process to narrow it down

dmesg and PFL help with diagnosing crashes due to libraries, but I don’t think that would help here

If it helps, here’s my package.env:

# Build failures
app-emulation/wine-vanilla noflto O3
sys-apps/groff O3
dev-lang/rust noflto
dev-lang/python O3
sys-auth/polkit O3
sys-libs/libomp noflto
sys-libs/compiler-rt noflto
net-libs/nodejs O3
dev-lang/duktape O3
x11-drivers/xf86-video-intel noflto

# Runtime failures
gnome-extra/cjs noflto O3
sys-devel/llvm noflto