https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71135 --- Comment #3 from Yaakov Selkowitz <yselkowi at redhat dot com> --- It seems that #define _GLIBCXX_USE_WEAK_REF 1 would fix this; the question is where exactly it should go (config/os/generic/os_defines.h ?) and under what conditions.