https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78551
--- Comment #11 from Nathan Sidwell <nathan at gcc dot gnu.org> --- Created attachment 40276 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=40276&action=edit non-union crash Union is not necessary to trigger the ICE. All we need is to initialize a char array with a string constant, and then try and write an element of the array.