Building devcontainers with Rider 2025.2 and ASP.NET Core

Question

I built a devcontainer on Windows, via Rider 2025.2, and I could run it and launch the rider IDE then load the project.

When I build or restore nuget packages in the project, using dotnet command, I get No error! Everything runs well!

But when I build the project with Rider, I get this silly error:

0>Microsoft.PackageDependencyResolution.targets(266,5): Error MSB4018 : The "ResolvePackageAssets" task failed unexpectedly.
NuGet.Packaging.Core.PackagingException: Unable to find fallback package folder 'C:\Program Files (x86)\Microsoft Visual Studio\Shared\NuGetPackages'.
 at NuGet.Packaging.FallbackPackagePathResolver..ctor(String userPackageFolder, IEnumerable`1 fallbackPackageFolders)
 at Microsoft.NET.Build.Tasks.NuGetPackageResolver.CreateResolver(IEnumerable`1 packageFolders)
 at Microsoft.NET.Build.Tasks.ResolvePackageAssets.CacheWriter..ctor(ResolvePackageAssets task)
 at Microsoft.NET.Build.Tasks.ResolvePackageAssets.CacheReader.CreateReaderFromDisk(ResolvePackageAssets task, Byte[] settingsHash)
 at Microsoft.NET.Build.Tasks.ResolvePackageAssets.CacheReader..ctor(ResolvePackageAssets task)
 at Microsoft.NET.Build.Tasks.ResolvePackageAssets.ReadItemGroups()
 at Microsoft.NET.Build.Tasks.ResolvePackageAssets.ExecuteCore()
 at Microsoft.NET.Build.Tasks.TaskBase.Execute()
 at Microsoft.Build.BackEnd.TaskExecutionHost.Execute()
 at Microsoft.Build.BackEnd.TaskBuilder.ExecuteInstantiatedTask(TaskExecutionHost taskExecutionHost, TaskLoggingContext taskLoggingContext, TaskHost taskHost, ItemBucket bucket, TaskExecutionMode howToExecuteTask)

This error clearly shows a Windows path, despite the fact that the container's image is linux, the files are in a Linux file system, and everything .NET in the project's container is on Linux. Only the host OS is Windows.

I searched a solution extensively and could only find a solution to this problem on VS Code, but not on Rider! Does anyone know how to resolve this annoying error ?

• kf-jb: Could you check the value of <RestoreFallbackFolders> in your csproj? It looks like Rider might be incorrectly expanding special value in this property
• Pieterjan: You need to use this props/targets file to separate the windows/Linux build. Then remove the bin/obj folders and restart VS
• Damien Doumer: @kf-jb I didn't set a value for "RestoreFallbackFolders"
• Pieterjan: It should. Did you shutdown VS, remove all bin/obj folders + the .vs folder, remove your devcontainer image through Docker Desktop, and restart visual studio, then open your devcontainer? It should work if the files are in the repository root. I use it all the time
• Pieterjan: I just created a demo repository here with the expected result