[Proposal] Deprecate .NET 6/7 support in favor of .NET 8 in fall release about dotnet-sdk

[philliphoff]

@WhitWaldo Post-November '24 I think it will be easy to drop .NET 7 (which mostly wasn't directly targeted) and add .NET 9. Dropping .NET 6 at that point might be more difficult. While it will be out of support, yes, given how long it seemed to take for it to be adopted from .NET FW and .NET Core 3.0/3.1, I wonder how quickly we can assume people will move from .NET 6 to .NET 8. (Granted, that jump should be easier than prior jumps.) I might be inclined to wait an extra release cycle before dropping .NET 6.

[WhitWaldo]

Has there been any discussion amongst the .NET maintainers about the value of even having explicit support for the non-LTS .NET releases?

I recently contributed to a project that's still maintaining a release for .NET Core 3.0 and I found I didn't even have the build tools installed to compile it locally, which upped the difficulty of providing my contribution. It'd be a real shame to have a similar problem here of would-be contributors wanting to provide support for latest and greatest releases but being blocked merely because they don't have the older SDKs installed.

[philliphoff]

@WhitWaldo That's a fair concern (especially if we intend to keep support for versions past their LTS dates). One option might be to tweak the projects/targets such that only the current LTS version is targeted when building/testing locally and have the CI pipelines build/test/package the rest of the supported matrix.