https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96819
--- Comment #9 from Patrick Palka <ppalka at gcc dot gnu.org> --- Is this with -std=c++20 or -std=c++17? From what I can tell r11-2747 adds a fragment of code that is run only for c++20, and then r11-2748 makes it run for c++17 as well. And only the first commit was backported to the 10 branch.