https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91767
--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> --- For building gcc with ubsan, you should configure --with-build-config=bootstrap-ubsan, rather than trying to inject the flags in other ways. Anyway, for the ICE, it would be interesting to put a breakpoint where the general_scalar_constructor object is constructed and see how the subobject is initialized (before anything is added into the hash_map) when compiled with clang.
