https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80922
--- Comment #10 from pefoley2 at pefoley dot com --- It does? I wasn't aware of that. My read of the configure options is that the two options are tangential. And from a quick skim, I couldn't find anything that made enabling lto suppress Werror. Besides, regardless of whether it's supported or not, it's another example of this issue in the wild.