https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92778
--- Comment #4 from Hannes Hauswedell <h2+bugs at fsfe dot org> --- Thanks for the quick reply, Jonathan! I am familiar with the error in general, but I am using vanilla packages by the vendor (FreeBSD) which should not have any funky optimisations. Also, my colleague just reported that she is seeing the same on gcc9 on Ubuntu -- I'll try to confirm that myself. The code is not expected to build on trunk/gcc10 because of other known and reported issues (strip_typedefs...), so I think what you are seeing is not the same thing.