DOTNET_ROLL_FORWARD=Major has been removed from .NET 10 SDK images

[lbussell]

The July 14th, 2026 update to .NET 10 (and .NET 11 Preview) SDK container images removes the global DOTNET_ROLL_FORWARD=Major environment variable.

This variable was added in .NET 10 Preview 1 as a temporary compatibility workaround for PowerShell and unintentionally remained after PowerShell was updated. It has been removed to prevent unexpected behavior.

Impact

This may cause Docker builds or CI jobs to fail when they run a .NET tool that targets an older runtime not installed in the SDK image. It also prevents tests targeting older .NET versions from silently running on a newer runtime.

Action required

If your build depends on major-version roll-forward, explicitly enable it in your Dockerfile:

ENV DOTNET_ROLL_FORWARD=Major

Alternatively, install the runtime required by the application or update the application or tool to target a runtime included in the SDK image.

Related:

• Global DOTNET_ROLL_FORWARD=Major in SDK images can silently change test runtime behavior #7255
• Remove DOTNET_ROLL_FORWARD environment variable from .NET 10 and 11 SDK images #7256