https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77550
--- Comment #14 from Markus Trippelsdorf <trippels at gcc dot gnu.org> --- The reduced testcase needs libstdc++.so from trunk. Otherwise you'll get undefined reference errors to _ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE12_Alloc_hiderC1EPcOS3_ .