https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109808
--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> --- Backported as r12-9530-g16a76499f916b5 so I hope this is fixed now (I still can't reproduce it even with a --with-default-libstdcxx-abi=gcc4-compatible build).
