[Bug c++/124928] [modules] "was not declared in this scope" error

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124928

--- Comment #3 from d7d1cd <d7d1cd at mail dot ru> ---
Minimal example:
    $ cat foo.h
    #pragma once
    class Foo {};

    $ cat foo.ixx
    module;
    #include "foo.h"
    export module M : foo;
    export using ::Foo;

    $ cat bar.h
    #pragma once
    #include "foo.h"
    struct Bar {
        Foo f;
    };

    $ cat bar.ixx
    module;
    #include "bar.h"
    export module M : bar;
    export using ::Bar;

    $ cat module.ixx
    export module M;
    export import : bar;
    export import : foo;

    $ cat main.cc
    import M;
    int main() { 
        Foo f;
    }

Compilation and error:
    $ g++ -std=c++23 -fmodules foo.ixx bar.ixx module.ixx main.cc
    main.cc: In function ‘int main()’:
    main.cc:5:5: error: ‘Foo’ was not declared in this scope
        5 |     Foo f;
          |     ^~~