https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99284
--- Comment #1 from Alexander Lelyakin <alexander.lelyakin at googlemail dot
com> ---
There is a shorter sequence:
g++ -std=c++20 -fmodules-ts -x c++-system-header unordered_map
g++ -std=c++20 -fmodules-ts -x c++-system-header regex
----
/usr/local/include/c++/11.0.1/regex: internal compiler error: in key_mergeable,
at cp/module.cc:10456
0x6e1dd9 trees_out::key_mergeable(int, merge_kind, tree_node*, tree_node*,
tree_node*, depset*)
../../gcc/gcc/cp/module.cc:10456
0xa5a8f1 trees_out::decl_value(tree_node*, depset*)
../../gcc/gcc/cp/module.cc:7769
0xa625c3 depset::hash::find_dependencies(module_state*)
../../gcc/gcc/cp/module.cc:13237
0xa62c28 module_state::write(elf_out*, cpp_reader*)
../../gcc/gcc/cp/module.cc:17652
0xa640cf finish_module_processing(cpp_reader*)
../../gcc/gcc/cp/module.cc:19922
0x9f776b c_parse_final_cleanups()
../../gcc/gcc/cp/decl2.c:5175
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.
----
g++ (GCC) 11.0.1 20210228 (experimental)
