[SOLVED] sys-libs/glibc-2.42-r5 missing symbols for avx512

ololoshwin · Post by **ololoshwin** » Wed Mar 25, 2026 2:46 pm

I've installed sys-libs/glibc-2.42-r5:2.2::gentoo with FEATURES="splitdebug"

Unfortunately I can't find glibc function names in the back-traces and can't set working breakpoints to strlen()

strlen@plt redirect to the avx512 implementation.

Is it a bug?

GDH-gentoo · Post by **GDH-gentoo** » Wed Mar 25, 2026 9:08 pm

GNU libc's code is not the easiest to read, but, if I understand correctly, strlen() is defined as an indirect function on amd64, so that would match what you observe. It looks like the "resolver function" is named strlen_ifunc(), and the actual implementations, __strlen_variant() (e. g. __strlen_avx2, __strlen_evex, etc.).

ololoshwin · Post by **ololoshwin** » Thu Mar 26, 2026 5:42 pm

Found out USE=multiarch causing this weird things.

ololoshwin · Post by **ololoshwin** » Thu Mar 26, 2026 10:25 pm

My bad. Real issue was missing -ggdb in CFLAGS and producing incomplete debug file. Now it works with multiarch too.