为何NuGet引用指向FallbackFolder？ASP.NET Core新手求助

Hey there! Let's break this down for you since you're new to ASP.NET Core—no need to worry, this is totally normal behavior in most cases.

Why NuGet is Using FallbackFolder #

• SDK-included packages: Many official Microsoft packages (like Microsoft.EntityFrameworkCore and its dependencies) come pre-installed alongside the ASP.NET Core SDK. These packages are stored in the FallbackFolder, which acts as a local, offline-ready source. NuGet prioritizes this local source over downloading from remote feeds like nuget.org, which speeds up package resolution and works even when you're offline.
• Version compatibility: The packages in FallbackFolder are specifically matched to the version of the .NET/ASP.NET Core SDK you’re using. For example, if you’re working with the .NET 6 SDK, the EF Core package in FallbackFolder is guaranteed to be compatible with .NET 6, avoiding frustrating version mismatch issues.
• NuGet's source priority: FallbackFolder is part of NuGet’s local source hierarchy. When resolving packages, NuGet first checks local sources (including FallbackFolder, user cache, and project-local packages) before reaching out to remote feeds. This is a built-in optimization to make package management faster and more reliable.

Do You Need to Fix This? #

Short answer: No, not if your app is working correctly right now.

• This is an intended, normal behavior of NuGet and the ASP.NET Core SDK. It won’t cause any issues with your development, testing, or deploying your app.
• If you ever need a specific version of Microsoft.EntityFrameworkCore that’s different from the SDK-provided one, you can manually update the package via the NuGet Package Manager or run the dotnet add package Microsoft.EntityFrameworkCore --version [YourDesiredVersion] command. NuGet will then download the desired version from the remote source and replace the FallbackFolder reference.
• Only consider troubleshooting if you run into package loading errors. In that case, you can clear your NuGet cache with this command:

  dotnet nuget locals all --clear
  

  Then restore packages again to let NuGet re-fetch them from the appropriate source.

Since your app is functioning fine, just keep building your project—this is a common, harmless pattern you’ll see with other Microsoft-owned packages as you dive deeper into ASP.NET Core!

内容的提问来源于stack exchange，提问作者B.Pumpkin