https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67047
--- Comment #3 from Anders Granlund <anders.granlund.0 at gmail dot com> --- It seems like the increment of the enumerator x triggered the use of the following compiler extension: https://gcc.gnu.org/onlinedocs/gcc/_005f_005fint128.html This without any error messages. That is not ok! Remember that we used -pedantic-errors.