msvc module bug undefined object

COMPILE_COMMANDS.md

Steps to reproduce the bug:

• First open a VS developer shell using Visual Studio Version 17.5.0 Preview 6.0
• Compile first with cl /nologo /std:c++latest /EHsc main.cpp compilation should succeed.
• Compile again with cl /nologo /std:c++latest /EHsc /DMODULES mod.ixx main.cpp you will now see an error like

C:\Users\anon\dev\TestInclude.h(13): error C2079: 'storage<Object>::value' uses undefined class 'Object'
main.cpp(8): note: see reference to class template instantiation 'storage<Object>' being compiled

main.cpp

#ifdef MODULES
import mod;
#else
template <typename T>
struct ptr { T* p; };
class obj : public ptr<class value> {};
class value { obj v; };
#endif

int main() {
    obj o;
}

mod.ixx

export module mod;
template <typename T>
struct ptr { T* p; };
export class obj : public ptr<class value> {};
export class value { obj v; };