Fix -extra container variant check to support .NET 9+

[Copilot]

The -extra base image variant was only applied for .NET 8 due to an equality check instead of a range check, breaking support for .NET 9 and later.

Changes

• Fixed version comparison in ComputeDotnetBaseImageAndTag.cs:

  • Changed parsedVersion.Major == FirstVersionWithNewTaggingScheme to parsedVersion.Major >= FirstVersionWithNewTaggingScheme
  • Ensures .NET 8+ applications using chiseled containers without InvariantGlobalization correctly receive the -extra variant containing ICU and tzdata

• Added test coverage for .NET 9 and .NET 10:

  • FDDConsoleAppWithCulturesAndOptingIntoChiseledGetsExtrasForNet9AndLater
  • FDDAspNetAppWithCulturesAndOptingIntoChiseledGetsExtrasForNet9AndLater
  • Verify console and ASP.NET apps get correct -extra tags for future SDK versions

Context

The -extra variants became available starting with .NET 8's new tagging scheme. The original implementation incorrectly hard-coded the version check to exactly 8, preventing the logic from working with newer SDK versions.

// Before: Only .NET 8
&& (!parsedVersion.IsPrerelease && parsedVersion.Major == FirstVersionWithNewTaggingScheme)

// After: .NET 8 and all future versions
&& (!parsedVersion.IsPrerelease && parsedVersion.Major >= FirstVersionWithNewTaggingScheme)

Original prompt

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This section details on the original issue you should resolve

<issue_title>How to use "-extra" base image via InvariantGlobalization?</issue_title>
<issue_description>This is a bug in the containers targets - when we check if we can add the -extra variant to the users' ContainerFamily, we check if the target runtime == 8, not >= 8 (when the -extras first became available).

We should fix this comparison and add tests to the existing targets test to verify the expected behavior.

Discussed in #52158

^{Originally posted by mu88 December 15, 2025}
Hi @baronfel,

When using the .NET SDK Container Building Tools and setting the MSBuild property InvariantGlobalization to false, the base image with the -extra suffix is not used:

Based on the log statement Using user-provided ContainerFamily, I was able to find this spot in the code.
However, I'm wondering about why I'm not ending up here 🤔

Do you have a hint for me?

Here's my repro workflow:

1. dotnet new webapi
2. dotnet publish /t:PublishContainer /p:InvariantGlobalization=false /p:ContainerRuntimeIdentifier=linux-x64 /p:ContainerFamily=noble-chiseled /bl
3. Open the MSBuild log with MSBuild Structured Log Viewer

</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes How to use "-extra" base image via InvariantGlobalization? #52160

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