http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45983
--- Comment #2 from Richard Guenther <rguenth at gcc dot gnu.org> 2010-10-12 13:22:33 UTC --- Older GCC for some reason complain about > g++-4.5 -S -std=c++0x synth.cpp -msse4 In file included from src/audio/synth_params.h:12:0, from src/audio/synth.h:18, from src/audio/synth.cc:41: src/core/sys_log.h: In function ‘void sys::log(const char*, ...)’: src/core/sys_log.h:95:40: error: invalid use of ‘__builtin_va_arg_pack ()’ reducing the canonical type error now.