https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94027
--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Nathan Sidwell <nat...@gcc.gnu.org>: https://gcc.gnu.org/g:191bcd0f30dd37dec773efb0125afdcae9bd90ef commit r10-7074-g191bcd0f30dd37dec773efb0125afdcae9bd90ef Author: Nathan Sidwell <nat...@acm.org> Date: Fri Mar 6 10:51:26 2020 -0800 Fix mangling ICE [PR94027] PR c++/94027 * mangle.c (find_substitution): Don't call same_type_p on template args that cannot match. Now same_type_p rejects argument packs, we need to be more careful calling it with template argument vector contents. The mangler needs to do some comparisons to find the special substitutions. While that code looks a little ugly, this seems the smallest fix.