How to test a custom module in MSVC's googletest - c++

Question

My project solution is roughly like this:
Project("{xxxxxxxxxxxxxxxx11111111}") = "project1", "project1.vcxproj", "{xxxxxxxxxxxxxxxx222222222222222}"
EndProject
Project("{xxxxxxxxxxxxxxxx11111111}") = "test", "test\test.vcxproj", "{xxxxxxxxxxxxxxxx333333333333333}"
EndProject
Project brief description:
I have two projects, one is the main project, the directory is project/src/balabala.ixx, and the other is the added googletest project, the directory is project/test/balabala.cpp
My requirement is to test whether the module of my main project meets my needs in the sub-project of googletest, but I can't use the module of the main project now, VS tells me that it can't find my module.
like this:
#include "gtest/gtest.h"
import std.core;
// cannot find my module
// import myproject.some_module;
TEST(TestCaseName, TestName)
{
EXPECT_EQ(1, 1);
EXPECT_TRUE(true);
// it works
std::cout << "hello world";
}
I also looked for Microsoft's documentation, and I found
https://devblogs.microsoft.com/cppblog/a-tour-of-cpp-modules-in-visual-studio/#external-modules
But it did not tell how to set the path, no matter the path I filled in is ../ or absolute path VS said that the target file cannot be opened
VC++ Directories -> all module is public -> true also not work :(
==========================================================================
After various attempts to no avail, I decided not to use the subproject. I copied the original include and lib folders of googletest to project/3rd-party/googletest, and then set up additional include directories and additional lib directories.
then I write this:
// project/test/test.cpp
#include <gtest/gtest.h>
// it found my module!!!
import muproject.some_module;
TEST(TestCaseName, TestName)
{
EXPECT_EQ(1, 1);
EXPECT_TRUE(true);
}
But when I choose to run the test case, the compiler outputs the following:
Build started...
1>------ Build started: Project: my_project, Configuration: Debug x64 ------
1>Scanning sources for module dependencies...
1>test.cpp
1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30037\include\sstream(262,1): error C2270: '()': modifiers not allowed on nonmember functions
1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30037\include\sstream(237): message : while compiling class template member function 'int std::basic_stringbuf<char,std::char_traits<char>,std::allocator<char>>::overflow(int)'
1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30037\include\sstream(905): message : see reference to class template instantiation 'std::basic_stringbuf<char,std::char_traits<char>,std::allocator<char>>' being compiled
1>`path_to_my_project`\3rd-party\googletest\include\gtest\gtest-message.h(232): message : see reference to class template instantiation 'std::basic_stringstream<char,std::char_traits<char>,std::allocator<char>>' being compiled
1>d:\a01\_work\3\s\binaries\x86ret\inc\compare(336,31): error C2028: struct/union member must be inside a struct/union
1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30037\include\sstream(262,1): fatal error C1903: unable to recover from previous error(s); stopping compilation
1>INTERNAL COMPILER ERROR in 'C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30037\bin\HostX86\x64\CL.exe'
1> Please choose the Technical Support command on the Visual C++
1> Help menu, or open the Technical Support help file for more information
1>Done building project "my_project.vcxproj" -- FAILED.
I double-checked the settings (x64/x86/debug/release) and confirmed that the lib settings are correct
gtest-message.h(232): message : see reference to class template instantiation 'std::basic_stringstream<char,std::char_traits,std::allocator>' being compiled
// We declare (but don't implement) this to prevent the compiler
// from implementing the assignment operator.
void operator=(const Message&);
// -> this line is line232
========================================================================
It's too strange, this seems to be a probabilistic event. If you don't import std.core, the compilation will generally pass, but once std.core is imported, it will most likely fail to compile (the error is as above) (but occasionally it can be compiled)