.NET 10 is dropping netstandard-targeting-pack-2.1

[omajid]

https://learn.microsoft.com/en-us/dotnet/core/distribution-packaging mentions the netstandard-targeting-pack-[netstandard_major].[netstandard_minor] package, which Linux distributors were encouraged to create and maintain.

With dotnet/sdk#50354, the contents that were included in the package are getting dropped. In other words, packagers should no longer create/ship netstandard-targeting-pack-2.1 with .NET 10.

The changes were made post Preview 7, and should be available in RC 1 RC 2.

FYI @dotnet/distro-maintainers

[omajid]

Would it be possible to avoid major packaging changes like this in the future, or to communicate these in advance before they happen?

Changing packages is like this is a major breaking change for us distro packagers who try and follow the packaging guidelines. When an entire subpackage is being removed, there's no simple fix to make things fall back such that the netstandard-targeting-pack-2.1 from .NET 9.0 is picked up over netstandard-targeting-pack-2.1 from .NET 10 Preview 7.

[MichaelSimons]

cc @baronfel, @marcpopMSFT

[baronfel]

Process wise, I think we could have an issue and PR label like 'impacts installer layout' or similar and have that label add a message notifying various groups or reminding us to do so. Similar to what we do for breaking change notifications.

[tmds]

there's no simple fix to make things fall back such that the netstandard-targeting-pack-2.1 from .NET 9.0 is picked up over netstandard-targeting-pack-2.1 from .NET 10 Preview 7.

I'd like to highlight this.

If I understand this correctly, it means systems that have the preview 7 installed will not install patch releases that come from .NET 9 for netstandard-targeting-pack-2.1. In other words: the netstandard-targeting-pack-2.1 package is not serviceable on these systems unless the distro maintainer start tinkering with its version number in .NET 9 builds.

[MichaelSimons]

cc @leecow for awareness.

[omajid]

I just figured out that this change missed RC 1 too. It will land in RC 2 first.