https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66146
--- Comment #26 from Paul Adobe <pmitchell.adbe at gmail dot com> --- It may be interesting to note that we recently ended up tracking a change in glibc to making this a problem on x86_64 architectures. Apparently when they refactored pthread_once in glibc patch 2.17.288 it changed the problem from an arm/powerpc only problem to an all-architecture problem. (cent7.7 had recently updated to .292, which made this quite evident)