https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98032
--- Comment #5 from Martin Liška <marxin at gcc dot gnu.org> --- Reduced test-case: $ cat vcldemo.ii namespace osl { class Thread { public: virtual ~Thread(); virtual void join(); }; } // namespace osl class SimpleReferenceObject { protected: virtual ~SimpleReferenceObject(); }; class Thread : SimpleReferenceObject, osl::Thread { public: osl::Thread::join; }; class RenderThread : Thread { RenderThread() { join(); } }; and a nice backtrace: $ /home/marxin/Programming/gcc2/objdir/gcc/xgcc -B /home/marxin/Programming/gcc2/objdir/gcc -O0 -Wall -fstack-protector-strong -c vcldemo.ii vcldemo.ii:14:3: warning: access declarations are deprecated in favour of using-declarations; suggestion: add the ‘using’ keyword [-Wdeprecated] 14 | osl::Thread::join; | ^~~ vcldemo.ii: In constructor ‘RenderThread::RenderThread()’: vcldemo.ii:17:25: internal compiler error: Segmentation fault 17 | RenderThread() { join(); } | ^ 0xb2168f crash_signal /home/marxin/Programming/gcc2/gcc/toplev.c:326 0x5b05d1 lookup_vfn_in_binfo(tree_node*, tree_node*) /home/marxin/Programming/gcc2/gcc/cp/class.c:2405 0x5a36d5 build_over_call /home/marxin/Programming/gcc2/gcc/cp/call.c:8300 0x5a53ae build_new_method_call_1 /home/marxin/Programming/gcc2/gcc/cp/call.c:9913 0x5a5dbf build_new_method_call(tree_node*, tree_node*, vec<tree_node*, va_gc, vl_embed>**, tree_node*, int, tree_node**, int) /home/marxin/Programming/gcc2/gcc/cp/call.c:9988 0x660cdd cp_parser_postfix_expression /home/marxin/Programming/gcc2/gcc/cp/parser.c:7361 0x6480fa cp_parser_binary_expression /home/marxin/Programming/gcc2/gcc/cp/parser.c:9461 0x648e17 cp_parser_assignment_expression /home/marxin/Programming/gcc2/gcc/cp/parser.c:9759 0x649051 cp_parser_expression /home/marxin/Programming/gcc2/gcc/cp/parser.c:9926 0x64bd25 cp_parser_expression_statement /home/marxin/Programming/gcc2/gcc/cp/parser.c:11524 0x655d5d cp_parser_statement /home/marxin/Programming/gcc2/gcc/cp/parser.c:11320 0x657488 cp_parser_statement_seq_opt /home/marxin/Programming/gcc2/gcc/cp/parser.c:11667 0x657540 cp_parser_compound_statement /home/marxin/Programming/gcc2/gcc/cp/parser.c:11621 0x66a3b0 cp_parser_function_body /home/marxin/Programming/gcc2/gcc/cp/parser.c:22693 0x66a3b0 cp_parser_ctor_initializer_opt_and_function_body /home/marxin/Programming/gcc2/gcc/cp/parser.c:22744 0x66d8dd cp_parser_function_definition_after_declarator /home/marxin/Programming/gcc2/gcc/cp/parser.c:27873 0x66ea29 cp_parser_late_parsing_for_member /home/marxin/Programming/gcc2/gcc/cp/parser.c:28760 0x6515e3 cp_parser_class_specifier_1 /home/marxin/Programming/gcc2/gcc/cp/parser.c:23693 0x6524cb cp_parser_class_specifier /home/marxin/Programming/gcc2/gcc/cp/parser.c:23719 0x6524cb cp_parser_type_specifier /home/marxin/Programming/gcc2/gcc/cp/parser.c:17462 Please submit a full bug report, with preprocessed source if appropriate. Please include the complete backtrace with any bug report. See <https://gcc.gnu.org/bugs/> for instructions.