https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82085
--- Comment #1 from Roland B <rbock at eudoxos dot de> --- Forgot to mention: The command line I used: /usr/local/gcc-trunk/bin/g++ -std=c++1z -Wall -Wpedantic -Wextra gcc-crash.cpp Output: gcc-crash.cpp:8:41: internal compiler error: Segmentation fault using type = char_sequence_t<name_of_v<T>>; ^~ 0xe281af crash_signal ../../trunk/gcc/toplev.c:341 0x8184ec tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool, bool) ../../trunk/gcc/cp/pt.c:17077 0x81c87b tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool) ../../trunk/gcc/cp/pt.c:16708 0x827552 tsubst_template_args ../../trunk/gcc/cp/pt.c:11805 0x82bd2b tsubst(tree_node*, tree_node*, int, tree_node*) ../../trunk/gcc/cp/pt.c:13982 0x82c208 tsubst(tree_node*, tree_node*, int, tree_node*) ../../trunk/gcc/cp/pt.c:13578 0x83c682 lookup_template_class_1 ../../trunk/gcc/cp/pt.c:8880 0x83c682 lookup_template_class(tree_node*, tree_node*, tree_node*, tree_node*, int, int) ../../trunk/gcc/cp/pt.c:9130 0x87b93d finish_template_type(tree_node*, tree_node*, int) ../../trunk/gcc/cp/semantics.c:3174 0x7dee18 cp_parser_template_id ../../trunk/gcc/cp/parser.c:15729 0x7defea cp_parser_class_name ../../trunk/gcc/cp/parser.c:22144 0x7d3ee0 cp_parser_qualifying_entity ../../trunk/gcc/cp/parser.c:6402 0x7d3ee0 cp_parser_nested_name_specifier_opt ../../trunk/gcc/cp/parser.c:6088 0x7ee9e1 cp_parser_simple_type_specifier ../../trunk/gcc/cp/parser.c:17055 0x7c9a2d cp_parser_type_specifier ../../trunk/gcc/cp/parser.c:16730 0x7ca9b2 cp_parser_type_specifier_seq ../../trunk/gcc/cp/parser.c:20976 0x7db074 cp_parser_type_id_1 ../../trunk/gcc/cp/parser.c:20819 0x7e3e51 cp_parser_type_id ../../trunk/gcc/cp/parser.c:20887 0x7e3e51 cp_parser_alias_declaration ../../trunk/gcc/cp/parser.c:18803 0x7e9b57 cp_parser_template_declaration_after_parameters ../../trunk/gcc/cp/parser.c:26549