Comment 3 for bug 1915640

// B_a.ii
template<typename _T1>
struct pair
{
  inline void Frob ();
};

// B_b.ii
import "./B_a.ii"

template<class _T1>
inline void pair<_T1>::Frob()
{ }

./cc1plus -quiet -std=c++20 -fmodule-header -fpreprocessed B_a.ii && ./cc1plus -quiet -std=c++20 -fmodule-header -fpreprocessed B_b.ii
B_b.ii:1: internal compiler error: in make_dependency, at cp/module.cc:12523
    1 | import "./B_a.ii" [[__translated]];
      |
0xcd61da depset::hash::make_dependency(tree_node*, depset::entity_kind)
 ../../../src/gcc/cp/module.cc:12523
0xcd7f54 depset::hash::add_class_entities(vec<tree_node*, va_gc, vl_embed>*)
 ../../../src/gcc/cp/module.cc:12942
0xce60bb module_state::write(elf_out*, cpp_reader*)
 ../../../src/gcc/cp/module.cc:17604

The module flags on the TEMPLATE_DECL do not match those of the DECL_TEMPLATE_RESULT.