https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118032
--- Comment #5 from Jeffrey A. Law <law at gcc dot gnu.org> --- Oh, on the pioneer. Hard to even guess. Given how under-powered each core is, if you don't keep them all busy it's going to be bad... So I'd be looking for a serialization problem in the build. Or your pcie might be fried. I'd check your system logs and see if any diagnostics were issued, particularly for whatever drives you've got. Ours would take absurdly long times for various operations presumably due to disk retries right before the whole thing would lose its mind. Basically the pioneer boxes are junk.
