https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99425
--- Comment #2 from Alexander Lelyakin <alexander.lelyakin at googlemail dot
com> ---
The same sequence now breaks earlier with different message:
g++ -std=c++20 -fmodules-ts -x c++-system-header map
g++ -std=c++20 -fmodules-ts -x c++-system-header vector
g++ -std=c++20 -fmodules-ts -x c++-system-header stdexcept
g++ -std=c++20 -fmodules-ts -x c++-system-header span
g++ -std=c++20 -fmodules-ts -x c++-system-header mutex
----
/usr/local/include/c++/11.0.1/mutex: internal compiler error: in key_mergeable,
at cp/module.cc:10366
0x6e249f trees_out::key_mergeable(int, merge_kind, tree_node*, tree_node*,
tree_node*, depset*)
../../gcc/gcc/cp/module.cc:10366
0xa5b3b5 trees_out::decl_value(tree_node*, depset*)
../../gcc/gcc/cp/module.cc:7625
0xa63251 depset::hash::find_dependencies(module_state*)
../../gcc/gcc/cp/module.cc:13139
0xa638e8 module_state::write(elf_out*, cpp_reader*)
../../gcc/gcc/cp/module.cc:17618
0xa64d7f finish_module_processing(cpp_reader*)
../../gcc/gcc/cp/module.cc:19858
0x9f835b 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.
----
g++ (GCC) 11.0.1 20210311 (experimental)
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This is free software; see the source for copying conditions. There is NO
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