https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94623
--- Comment #13 from David Binderman <dcb314 at hotmail dot com> --- (In reply to Iain Buclaw from comment #12) > (In reply to David Binderman from comment #11) > > Checking flag "extra" is the one. > > Without knowing too much about what that checking flag does. That would be > highly odd if that were the case, as the dmd implementation sits "outside" > of gcc. > > The only bridge that is connecting the two is d/d-system.h, which does some > necessary #define's to fix portability and use of gcc_assert. A possible next step is for you to try a build with checking flag extra switched on and see what happens. At least that would confirm or deny what I am seeing here. I don't think bootstrap is required.