https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81066
--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> --- I think the tsan build issue can be fixed just by replacing __res_state *statp = (__res_state*)state; line with struct __res_state *statp = (struct __res_state*)state; It should then build hopefully with both old and new glibc.