https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114103
--- Comment #10 from Jonathan Wakely <redi at gcc dot gnu.org> ---
This additional change should fix that:
--- a/libstdc++-v3/src/c++20/tzdb.cc
+++ b/libstdc++-v3/src/c++20/tzdb.cc
@@ -643,6 +643,7 @@ namespace std::chrono
void unlock() { infos_mutex.unlock(); }
};
+#if __cpp_lib_atomic_lock_free_type_aliases
#if defined __GTHREADS && __cpp_lib_atomic_wait
// Atomic count of unexpanded ZoneInfo objects in the infos vector.
// Concurrent access is allowed when all objects have been expanded.
@@ -704,6 +705,7 @@ namespace std::chrono
#endif // __GTHREADS && __cpp_lib_atomic_wait
RulesCounter<atomic_signed_lock_free> rules_counter;
+#endif // __cpp_lib_atomic_lock_free_type_aliases
#else // TZDB_DISABLED
_Impl(weak_ptr<tzdb_list::_Node>) { }
struct {
