https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83549
--- Comment #4 from Martin Liška <marxin at gcc dot gnu.org> --- (In reply to Jakub Jelinek from comment #3) > With current trunk: > > $ ./cc1plus -quiet pr83549.C > $ ./cc1plus -quiet pr83549.C -O1 > pr83549.C:4:4: error: generic thunk code fails for method ‘virtual void > C::_ZThn8_N1C3fooEz(...)’ which uses ‘...’ > C c; > ^ > > (likewise for -O2, -O3) on x86_64-linux. I see. I've got patch for that. My question is how did you isolate the testcase?