https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63226
--- Comment #1 from Tobias Burnus <burnus at gcc dot gnu.org> --- When simplifying the code names, I made a mistake. It should be "class TWO" and not "class ONE" in file two.ii. Hence, only the typedef'ed ynodetype and, hence, ynodetype are different. The classes are different. The ICE is the same in either case.