aspnetcore/docs/FallbackPackageCache.md

Fallback Package Cache (LZMA)

The fallback package cache (commonly called the LZMA) is a set of NuGet packages that are bundled in the .NET Core SDK installers. The LZMA is a compressed file format, similar to a .zip. On first use or on install, the .NET Core CLI will expand this LZMA file, extracting the packages inside to %DOTNET_INSTALL_DIR%/sdk/NuGetFallbackFolder.

Requirements

The following requirements are used to determine which packages go into the fallback package cache:

• A user should be able to restore the following templates and only use packages from the offline cache:
  • dotnet new console
  • dotnet new library
  • dotnet new web
  • dotnet new razor
  • dotnet new mvc

The following packages are NOT included in the offline cache.

• Packages required for standalone publishing, aka projects that set a Runtime Identifier during restore
• Packages required for F# and VB templates
• Packages required for Visual Studio code generation in ASP.NET Core projects
• Packages required to restore .NET Framework projects
• Packages required to restore test projects, such as xunit, MSTest, NUnit

The result of this typically means including the transitive graph of the following packages:

• Packages that match bundled runtimes
  • Microsoft.NETCore.App
  • Microsoft.AspNetCore.App
  • Microsoft.AspNetCore.All
• Packages that Microsoft.NET.Sdk adds implicitly
  • Microsoft.NETCore.App
  • NETStandard.Library
• Packages that are a PackageReference/DotNetCliToolReference in basic ASP.NET Core templates. In addition to packages above, this typically includes:
  • Microsoft.EntityFrameworkCore.Tools{.DotNet}
  • Microsoft.VisualStudio.Web.CodeGeneration.Design
  • Microsoft.VisualStudio.Web.BrowserLink

Example

Given the following parameters:

• LatestNETCoreAppTFM = netcoreapp2.1
• DefaultRuntimeVersion = 2.1
• BundledRuntimeVersion = 2.1.8
• BundledAspNetRuntimeVersion = 2.1.7
• LatestNETStandardLibraryTFM = netstandard2.0
• BundledNETStandardLibraryVersion = 2.0.1

The LZMA should contain

• Microsoft.NETCore.App/2.1.0 + netcoreapp2.1 dependencies (Microsoft.NET.Sdk will implicitly reference "2.1", which NuGet to 2.1.0)
• Microsoft.NETCore.App/2.1.8 + netcoreapp2.1 dependencies (Matches the runtime in shared/Microsoft.NETCore.App/2.1.8/)
• Microsoft.AspNetCore.All/2.1.7 + netcoreapp2.1 dependencies (Matches the runtime in shared/Microsoft.AspNetCore.All/2.1.7/)
• NETStandard.Library/2.0.1 + netstandard2.0 dependencies (Microsoft.NET.Sdk will implicitly reference "2.0.1")