Discourage using explicit package references to ILCompiler to publish

[LakshanF]

Fixes #74387 and dotnet/sdk#27239

Publishing a NativeAOT application is supported via the SDK and the 'old' unsupported way that we started via adding explicit package reference is discouraged. The explicit support is for very narrow scenarios like getting the latest fix on native AOT issues before the SDK exposes the fix via its official ILCompiler packages.

We also no longer support publishing an AOT application if the SDK property, PublishAOT, is not set and only the explicit package reference exists. We allowed this behavior (no PublishAOT specified) early in 7.0 when SDK support was not enabled but do not want to continue to support the old way now. SDK path is the only we way want to support except for the narrow scenario described above where PublishAOT is still required for that scenario to work.

[jkotas]

I am wondering whether we should kill the feature that automatically turns on PublishAot when the package is explicitly references. It would steer people towards just using the PublishAot property. Thoughts?

[LakshanF]

I am wondering whether we should kill the feature that automatically turns on PublishAot when the package is explicitly references. It would steer people towards just using the PublishAot property. Thoughts?

I like that that but that would break any existing usage of that pattern from 7.0 onwards. The warning text in this change would only be triggered when PublishAOT is set to true (and an explicit reference exist). Is that ok?

[jkotas]

The warning text in this change would only be triggered when PublishAOT is set to true (and an explicit reference exist). Is that ok?

I think it is ok. People are going to quickly learn that the package reference alone does not do anything.

If we want to do this, it would be nice to get this into 7.0 to avoid 7.0->8.0 breaking change around what the package reference does.

[sbomer]

Thank you, LGTM.

[LakshanF]

/azp run runtime-extra-platforms

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[LakshanF]

/backport to release/7.0

[github-actions]

Started backporting to release/7.0: https://github.com/dotnet/runtime/actions/runs/2948185603

[github-actions]

@LakshanF an error occurred while backporting to release/7.0, please check the run log for details!

Error: @LakshanF is not a repo collaborator, backporting is not allowed. If you're a collaborator please make sure your dotnet team membership visibility is set to Public on https://github.com/orgs/dotnet/people?query=LakshanF

[LakshanF]

/backport to release/7.0

[github-actions]

Started backporting to release/7.0: https://github.com/dotnet/runtime/actions/runs/2950238449

[github-actions]

@LakshanF an error occurred while backporting to release/7.0, please check the run log for details!

Error: @LakshanF is not a repo collaborator, backporting is not allowed. If you're a collaborator please make sure your dotnet team membership visibility is set to Public on https://github.com/orgs/dotnet/people?query=LakshanF

[danmoseley]

/backport to release/7.0

[github-actions]

Started backporting to release/7.0: https://github.com/dotnet/runtime/actions/runs/2950265406

[github-actions]

@danmoseley backporting to release/7.0 failed, the patch most likely resulted in conflicts:

$ git am --3way --ignore-whitespace --keep-non-patch changes.patch

Applying: Show a warning when an explicit package reference to ILCompiler is added
Applying: Apply suggestions from code review
Applying: Fix issue 27239
Applying: Apply suggestions from code review
Applying: exclude the warning for direct targets file invoke cases
Using index info to reconstruct a base tree...
M	src/coreclr/nativeaot/BuildIntegration/Microsoft.DotNet.ILCompiler.SingleEntry.targets
Falling back to patching base and 3-way merge...
Auto-merging src/coreclr/nativeaot/BuildIntegration/Microsoft.DotNet.ILCompiler.SingleEntry.targets
CONFLICT (content): Merge conflict in src/coreclr/nativeaot/BuildIntegration/Microsoft.DotNet.ILCompiler.SingleEntry.targets
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0005 exclude the warning for direct targets file invoke cases
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".
Error: The process '/usr/bin/git' failed with exit code 128

Please backport manually!