Access to a private member - Rebuild of the Debian archive with clang

"Access to a private member" build failure(s) — clang 11.0.0

This code is accepted by g++ but refused by clang.
gcc bug #52373 has been reported, which is a duplicate of the bug #41437.

class A
{
    struct st
    {
        static void f();
    };
};

template <typename t> void foo()
{
    A::st::f();
}

Package	Version	Supposed error message	Full log	Bug report
openfoam	1906.191111+dfsg1-2	lnInclude/IListStream.H:161:13: error: 'List' is a private member of 'Foam::List'	Log

1 errors