https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98538
Nathan Sidwell <nathan at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |ASSIGNED --- Comment #5 from Nathan Sidwell <nathan at gcc dot gnu.org> --- I don;t think your patch is quite right. the call afterwards is making the assumption that DEPENDENT_TYPE_P is only ever set when DEPENDENT_TYPE_P_VALID is true, and as I discovered, that is not correct. see this code near pt.c:14899 set_underlying_type (r); if (TYPE_DECL_ALIAS_P (r)) /* An alias template specialization can be dependent even if its underlying type is not. */ TYPE_DEPENDENT_P_VALID (TREE_TYPE (r)) = false; } I did wonder if we should just recalculate properly there though ... 'tis annoying that 'taking' a bug does not put it in the assigned state :(