10.0.102 Breaking Change: Removal of rtm Branding

[mthalman]

Breaking Change: Removal of rtm Branding

Description

For the .NET 10.0.102 release (scheduled for January 2026) there is a breaking change to be aware of in the build.sh script. PR dotnet/dotnet#3574 updates .NET’s source-build branding behavior by removing support for the historical rtm branding value and delegating all default branding decisions to the VMR orchestrator. Downstream distro maintainers who previously supplied explicit branding parameters — particularly --branding rtm — must update their build scripts, as this value is no longer valid and will cause build failures.

Version Introduced

10.0.102

Previous Behavior

• Downstream maintainers could pass --branding rtm to the build.sh script to produce "RTM" release builds.
• The build system implicitly accepted rtm as a valid branding kind.
• Maintainers relied on this value to ensure their source-build output matched release branding expectations.

New Behavior

• The rtm branding value is no longer supported by the build.sh script and now results in a build error.

• Branding is now driven by the orchestrator through the new property RepoDotNetFinalVersionKind, which determines the appropriate default based on repository and branch context.

• Only the following branding values are now supported:

  • repodefault
  • unstable
  • preview
  • release

• Most source-build scenarios no longer require maintainers to supply a branding argument at all—the build defaults will produce appropriate release or preview branding automatically.

Reason for Change

The historical rtm branding keyword was inconsistent with current versioning terminology and was not aligned with how the VMR orchestrator determines release or preview branding states. This change simplifies the branding model, standardizes the allowed values, and ensures consistent versioning across the unified VMR-based build.

Recommended Action

• Remove all usage of --branding rtm for calls to the build.sh script.
• In typical distro source-build workflows, no explicit branding parameter is required or expected.
• If explicit branding is needed, replace it with one of the supported values:
  • release
  • preview
  • unstable
  • repodefault
• For more information see Allow default branding to be set by the VMR orchestrator dotnet#3574