[rxcpp] find_package(rxcpp "4.1.1" CONFIG REQUIRED) fails because of wrong version info

[midrare]

Library name: rxcpp
New version number: 4.1.1

find_package(rxcpp "4.1.1" CONFIG REQUIRED) fails with the following error.

CMake Error at C:/opt/vcpkg/scripts/buildsystems/vcpkg.cmake:844 (_find_package):
  Could not find a configuration file for package "rxcpp" that is compatible
  with requested version "4.1.1".

  The following configuration files were considered but not accepted:

    C:/Users/User/hello/cmake-build-debug/vcpkg_installed/x64-windows/share/rxcpp/rxcppConfig.cmake, version: 2.2.4

It seems that rxcppConfigVersion.cmake hasn't been updated to match the new package version.

[FrankXie05]

@mediumrarez Please delete the local rxcpp cache and install rxcpp again.

[midrare]

I deleted cmake-build-debug, and vcpkg_installed, then reinstalled everything but the error still persists.

I'm running in manifest mode. Do I need to delete the global vcpkg cache too?

[FrankXie05]

I have not reproduced it, could you please provide me with your sample project file? :)

This is my example project :

# CMakeList.txt : CMake project for usage, include source and define
# project specific logic here.
#
cmake_minimum_required (VERSION 3.8)

project(test)
# Add source to this project's executable.
add_executable (usage "usage.cpp" "usage.h")

# TODO: Add tests and install targets if needed.
find_package(rxcpp CONFIG REQUIRED)
target_link_libraries(usage PRIVATE rxcpp)

PS E:\port-update\vcpkg> ./vcpkg install rxcpp:x64-windows
 Computing installation plan...                                                
 The following packages will be built and installed:                          
    rxcpp[core]:x64-windows -> 4.1.1#1                                           
 Detecting compiler hash for triplet x64-windows...                           
 A suitable version of powershell-core was not found (required v7.2.8) Downloading portable powershell-core 7.2.8...      
 Downloading powershell-core...                                                                                           
 https://github.com/PowerShell/PowerShell/releases/download/v7.2.8/PowerShell-7.2.8-win-x86.zip->E:\port-update\vcpkg\downloads\PowerShell-7.2.8-win-x86.zip       
 Downloading https://github.com/PowerShell/PowerShell/releases/download/v7.2.8/PowerShell-7.2.8-win-x86.zip                                                     
 Extracting powershell-core...                                                                                                                                 
 Restored 0 package(s) from C:\Users\test\AppData\Local\vcpkg\archives in 316.6 us. Use --debug to see more details.                                    
 Installing 1/1 rxcpp:x64-windows...                                                                                                                          
 Building rxcpp[core]:x64-windows...                                                                                                                          
 -- Downloading https://github.com/ReactiveX/RxCpp/archive/v4.1.1.tar.gz -> ReactiveX-RxCpp-v4.1.1.tar.gz...                                                   
 -- Extracting source E:/port-update/vcpkg/downloads/ReactiveX-RxCpp-v4.1.1.tar.gz                                                                             
 -- Applying patch disable-tests.patch                                                                                                                         
 -- Using source at E:/port-update/vcpkg/buildtrees/rxcpp/src/v4.1.1-aae9c762a3.clean                                                                          
 -- Configuring x64-windows                                                                                                                                   
 -- Building x64-windows-dbg                                                                                                                                 
 -- Building x64-windows-rel                                                                                                                                 
 -- Performing post-build validation                                                                                                                         
 Stored binary cache: "C:\Users\test\AppData\Local\vcpkg\archives\b7\b7d2718f25cd79c64355a6c00af2a849093d982782a6f46edd55ea58ab6927e4.zip"             
 Elapsed time to handle rxcpp:x64-windows: 32.9 s                                                                                                            
 Total install time: 1.014 min                                                                                                                               
 rxcpp provides CMake targets: 
 
    # this is heuristically generated, and may not be correct                                                                                                 
    find_package(rxcpp CONFIG REQUIRED)                                                                                                                       
    target_link_libraries(main PRIVATE rxcpp) 
    
 PS E:\port-update\vcpkg> 

[midrare]

You're missing the version specifier. I can reproduce with your sample CMakeLists.txt by adding the version specifier.

find_package(rxcpp "4.1.1" CONFIG REQUIRED)
                    ^^^^^

---

For completeness, here is the CMakeLists.txt I used:

# CMakeList.txt : CMake project for usage, include source and define
# project specific logic here.
#
cmake_minimum_required (VERSION 3.8)

project(test)
# Add source to this project's executable.
add_executable (usage "usage.cpp" "usage.h")

# TODO: Add tests and install targets if needed.
find_package(rxcpp "4.1.1" CONFIG REQUIRED)
target_link_libraries(usage PRIVATE rxcpp)

Here's the vcpkg.json

{
    "$schema": "https://raw.githubusercontent.com/microsoft/vcpkg/master/scripts/vcpkg.schema.json",
    "name": "demo",
    "version-semver": "0.1.0",
    "builtin-baseline": "ae826fceaa15109814d0531faeda424f43047822",
    "dependencies": [
        {
            "name": "rxcpp",
            "version>=": "4.1.1"
        }
    ]
}

[FrankXie05]

Do you want to specify the port version?

[FrankXie05]

You're missing the version specifier. I can reproduce with your sample CMakeLists.txt by adding the version specifier.

I didn't add a version note because the default is looking for the latest version via CMAKE_TOOLCHAIN_FILE.

[midrare]

No, just the version of the actual library. The idea is so I can let the user choose if he wants to use vcpkg or not. If he doesn't want to use vcpkg, find_package() will still find the right version from his system.

[FrankXie05]

@mediumrarez At present, vcpkg only provides the latest port version. You can achieve it through manifest mode. But we can't provide such a method as find_package( xxx "version" CONFIG REQUIRED). :(
This will cause the project to find a version conflict between the config file provided by cmake and the config file provided by vcpkg.

[midrare]

Ok, I think I found the real issue, which is that upstream hasn't been updating their PROJECT_VERSION in the CMakeLists.txt file. I will try to resolve this upstream. Once upstream starts updating their PROJECT_VERSION then the vcpkg package version and the CMake package version should match.

ReactiveX/RxCpp#599

[FrankXie05]

@mediumrarez Regarding the last update upstream that happened nine months ago, I think we can only deal with it through patches. 🤔

[midrare]

@FrankXie05 Yes, I think so too. It doesn't look too hopeful.

[dg0yt]

Not a vcpkg bug IMO.

I think we can only deal with it through patches

If upstream doesn't suppport versions in find_package, I don't see a good reason to add it though patches. vcpkg has versioning by manifests.

[midrare]

@dg0yt The idea is to let the user choose whether or not to use vcpkg. If vcpkg isn't used, then find_package can still find the right version from the user's system.

[dg0yt]

@dg0yt The idea is to let the user choose whether or not to use vcpkg. If vcpkg isn't used, then find_package can still find the right version from the user's system.

There is nothing wrong with choice. However, I don't think this is a strong argument here:

• The defect is on upstream's side, and a vendored fix in vcpkg doesn't change it: Until it is fixed upstream, find_package can't reliably find the right pristine config from the user's system.
• Version control is not explicit control over whether vcpkg is used or not.
• Version is just one single aspect for choice of actual CMake config.
  There are many ways to guide find_package search in config mode.
• In general, find_package cannot ensure that there are no transitive ABI-level dependencies on vcpkg's build of the package when the user still consumes other vcpkg ports. To really exclude a particular package, one would need to provide an empty overlay port, letting vcpkg use the system package, too.

[midrare]

Until it is fixed upstream, find_package can't reliably find the right pristine config from the user's system.

Hmm... I guess you're right. Closing.