[Breaking change]: `RuntimeEnvironment.GetSystemVersion` no longer returns `ImageRuntimeVersion`

[richlander]

Description

Context: dotnet/runtime#87908

.NET 7 behavior: dotnet/runtime#87908 (comment)

.NET 8 behavior: dotnet/runtime#87908 (comment)

In the past, this API returns a .NET Framework-oriented value. That isn't useful. It has been updated to return a more relevant value, however, the historical leading v has been maintained.

We tried to fix this class of issues in the past, but missed this one:

Related:

• [Breaking Change] Improving .NET Core Version APIs runtime#12124
• Improve .NET Core version APIs runtime#28701
• [Breaking Change] Improving .NET Core Version APIs runtime#28788
• Breaking change: Update FrameworkName to ".NET" runtime#33680

Version

.NET 8 RC 1

Previous behavior

Return ImageRuntimeVersion

New behavior

Return "v" + Environment.Version

Type of breaking change

• Binary incompatible: Existing binaries may encounter a breaking change in behavior, such as failure to load or execute, and if so, require recompilation.
• Source incompatible: When recompiled using the new SDK or component or to target the new runtime, existing source code may require source changes to compile successfully.
• Behavioral change: Existing binaries may behave differently at run time.

Reason for change

The existing version wasn't useful or meaningful.

Recommended action

Update code to expect new version or use typeof(object).Assembly.ImageRuntimeVersion instead.

Feature area

Core .NET libraries

Affected APIs

RuntimeEnvironment.GetSystemVersion

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Associated WorkItem - 156742