0.88.0 → 0.89.0 — $quill mismatches are hard errors

A document's $quill: name@selector is the format it was written for. Through 0.88 the engine treated a divergence from the loaded quill as advisory: a wrong name produced a quill::ref_mismatch warning and rendered anyway, and the version selector was never checked. Both are now enforced — rendering a valid document against the wrong quill (a different format, or an incompatible version of one) yields undefined output, so it is rejected:

Condition	0.88	0.89
loaded quill's name ≠ $quill name	quill::ref_mismatch warning, render succeeds	quill::name_mismatch error
loaded quill's version outside the selector	unchecked, render succeeds	quill::version_mismatch error

Both raise the new RenderError::QuillMismatch, in render and dry_run. The name is checked first; a name mismatch leaves the version unevaluated (a selector belongs to a named quill).

QuillMismatch is distinct from ValidationFailed: the document is well-formed, just paired with the wrong quill. The remedy is to render with the referenced quill, or amend $quill — fix the name, or widen the selector to @3 / @latest. A bare name or @latest matches any version, so a document that targets its quill correctly never trips either check.

Migrating

Move the handling from the result's warnings to the thrown error / Err, and update the code:

- const result = quill.render(doc);
- if (result.warnings.some(w => w.code === "quill::ref_mismatch")) { … }
+ try {
+   const result = quill.render(doc);
+ } catch (err) {
+   // err.diagnostics[0].code is "quill::name_mismatch" or "quill::version_mismatch"
+ }

In Rust, add the variant to your render match:

  match quill.render(&doc, &opts) {
+     Err(RenderError::QuillMismatch { diags }) => handle_wrong_quill(diags),
      Err(RenderError::ValidationFailed { diags }) => handle_invalid_document(diags),
      …
  }

Python raises QuillmarkError as for any render failure; read the code off err.diagnostics.