Tracking issue for release notes of #124141: Remove Nonterminal and TokenKind::Interpolated

[rustbot]

This issue tracks the release notes text for #124141.

cc @nnethercote, @petrochenkov -- original issue/PR authors and assignees for drafting text

See the forge.rust-lang.org chapter about release notes for an overview of how the release team makes use of these tracking issues.

Release notes text

This section should be edited to specify the correct category(s) for the change, with succinct description(s) of what changed. Some things worth considering:

• Does this need an additional compat notes section?
• Was this a libs stabilization that should have additional headers to list new APIs under Stabilized APIs and Const Stabilized APIs?

# Compatibility Notes
- [Remove `Nonterminal` and `TokenKind::Interpolated`](https://github.com/rust-lang/rust/pull/124141). Certain invalid declarative macros that were previously accepted in obscure circumstances are now correctly rejected by the compiler. Use of a `tt` fragment specifier can often fix these macros.

Tip

Use the previous releases for inspiration on how to write the release notes text and which categories to pick.

Release blog section

If this change is notable enough for inclusion in the blog post then this section should be edited to contain a draft for the blog post. Otherwise leave it empty.

Note

If a blog post section is required the release-blog-post label should be added (@rustbot label +release-blog-post) to this issue as otherwise it may be missed by the release team.

[cuviper]

I'm confused why this was repurposed from #137517 to #124141, because only the former will be in 1.87. Several other PRs have referenced this relnote as well, so let me summarize their milestones:

• 1.87.0
  • Remove NtPat, NtMeta, and NtPath #137517
  • Remove NtItem and NtStmt #138083
  • Remove NtVis and NtTy #133436
• 1.88.0
  • Remove Nonterminal and TokenKind::Interpolated #124141
  • Remove NtExpr and NtLiteral #138478

Should the 1.87 compat note be more specific about what is changing now?
Should we repeat a compat note in 1.88 for the additional changes?

[nnethercote]

@cuviper: You are right. All five PRs are conceptually part of the same body of work, but they are split across 1.87 and 1.88. #124141 is the "parent" PR and the best single PR to point at to understand for the body of work. However, when I used it for the release notes I didn't notice that the PRs were split across two releases. It's possible that we'll see some minor breakage in both 1.87 and 1.88, so we should have compatibility entry for both 1.87 and 1.88. Is it possible for a compatibility entry to refer to multiple PRs? If so, we should probably do that for completeness.

Apologies for the lack of clarity here!

[cuviper]

It's possible that we'll see some minor breakage in both 1.87 and 1.88, so we should have compatibility entry for both 1.87 and 1.88.

Ok, how about re-opening #140488 for 1.88? The specifics are not terribly important for our relnotes tool, as long as each tracking issue has the desired milestone.

Is it possible for a compatibility entry to refer to multiple PRs? If so, we should probably do that for completeness.

It's freeform markdown, so we can say and link anything we like. In fact, I think the raw PR title, "Remove Nonterminal and TokenKind::Interpolated", is not useful in a compatibility note because those are internal implementation details. We only need to describe what users should know, and then link(s) allow finding more context -- which could be any/all of the PRs, or a specific comment, etc.