cmake + VS = "Microsoft.VisualStudio.ProjectSystem.References.UnresolvedBuildDependencyProjectReference" - c++

Question

I have a very simple CMake solution with one shared library and one executable.
CMakeLists.txt:
cmake_minimum_required(VERSION 3.24)
project(Test)
add_subdirectory(A)
add_subdirectory(B)
A/CMakeLists.txt:
cmake_minimum_required(VERSION 3.24)
set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
project(A)
file(GLOB_RECURSE Hdr CONFIGURE_DEPENDS inc/*)
file(GLOB_RECURSE Src CONFIGURE_DEPENDS src/*)
add_library(${PROJECT_NAME} SHARED ${Hdr} ${Src})
target_include_directories(${PROJECT_NAME} BEFORE PUBLIC inc PRIVATE src)
set_property(TARGET ${PROJECT_NAME} APPEND PROPERTY PUBLIC_HEADER ${Hdr})
A/CMakeLists.txt:
cmake_minimum_required(VERSION 3.24)
set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
project(B)
file(GLOB_RECURSE Src CONFIGURE_DEPENDS src/*)
add_executable(${PROJECT_NAME} ${Hdr} ${Src})
target_include_directories(${PROJECT_NAME} BEFORE PUBLIC inc PRIVATE src)
target_link_libraries(${PROJECT_NAME} PRIVATE A)
I use all these to generate a VS2022 solution and open it:
cmake.exe -S . -B tmp
start tmp\Test.sln
The CMake target "A" seems to be taken into consideration because I see the public headers folder (A/inc) amongst "Additional Include Directories" of VS project "B".
When I navigate in VS to B/References I see a reference to project "A" as expected:
but when I double-click it or try to see its properties , I get:
"Microsoft.VisualStudio.ProjectSystem.References.UnresolvedBuildDependencyProjectReference"
Is there a CMake+VS bug? or I do something wrong?
NOTE: if I create the entire solution by hand from Visual Studio (without CMake), it works fine!

Answer 1

I'm using CMake 3.24.1 and VS2019 and I'm facing the same problem. From what I see on my PC, I can conclude it's certainly not a CMake issue. That's because, after having used CMake to generate my VS Solution, I'm able to get rid of the problem by simply modifying the vcxproj file(s) inside my solution. However, there still is one thing I don't understand yet and what makes me to suspect VS having some kind of problem. Here is what I see/do.
My CMake generated solution contains one console application that depends on a number of static library projects: the projects are added to the application's References section. Now, when I double click on one of them I get the following message:
The Full Path property of the referenced project inside the Properties pane shows the same message.
To fix this I open the console application's vcxproj file and look for the following entry:
I remove the complete ProjectReferences element for each configuration, save the vcxproj file and restart my solution. In my case the problem is then solved: no more annoying message and the Full path property resolves to a valid path. But ...
Since I removed this ProjectReferences element the Link Library Dependencies property now defaults to Yes. I can verify this by opening the Property window and check the proper field. It shows Yes.
Now, I my case CMake generated a solution in which LinkLibraryDependencies was set to false. Therefore, I again open my console application's Property pane and set the Link Library Dependencies property back to false. I close the Property window and try rebuilding my project: no problem. Running the application: no problem.
When, after updating the Link Library Dependencies property with false inside the Property pane, I save my project and then open the vcxproj file using a text editor, I notice the ProjectReferences element has been added again. It's set to false. That is as expected. But, when close and I re-open the solution the initial problem is back again. However, when I change the ProjectReferences property value from false to true inside the vcxproj file using a text editor, the problem stays away after opening the solution!!
Based on the experience with my VS Solution, I come to the following conclusion:
I can get rid of the problem by removing the complete ProjectReferences element from the vcxproj file (use text editor) and then re-open the solution. But then the Link Library Dependencies property defaults to Yes
I can then change the Link Library Dependencies property back and forth to Yes and No without the problem shows up again. (Note: what I find strange is that the vcxproj file is not updated when I modify some properties and close the Property window.
When the application's project is saved to disk (vcxproj file gets updated), re-opening the solution will bring back the problem but only in case the Link Library Dependencies property was saved as false.
Maybe I overlook something, but this looks as a VS problem to me. Not a showstopper but annoying it is.