zed-industries/zed · error

no marker-bounded edit codeblocks found in model response

Error message

no marker-bounded edit codeblocks found in model response

What it means

The teacher-example parser scanned the model response for marker-bounded markdown code fences (after ruling out the NO_EDITS sentinel) and found none; the expected edit spans are absent, so the response cannot be parsed into edits.

Source

Thrown at crates/edit_prediction_cli/src/format_prompt.rs:430

        if response.trim().ends_with(Self::NO_EDITS) {
            return Ok(no_edits);
        }

        let prompt_inputs = example
            .prompt_inputs
            .as_ref()
            .context("example is missing prompt inputs")?;

        // The teacher emits reasoning plus a sequence of markdown code fences,
        // one per edit, each a marker-bounded span. Extract the spans from the
        // fences, then hand off to the shared hash-region patch assembler that
        // the student parser also uses.
        let codeblocks: Vec<String> = extract_all_codeblocks(response)
            .into_iter()
            .filter(|block| block.contains(hashed_regions::MARKER_TAG_PREFIX))
            .collect();
        if codeblocks.is_empty() {
            return Err(anyhow!(
                "no marker-bounded edit codeblocks found in model response"
            ));
        }

        let mut spans = Vec::with_capacity(codeblocks.len());
        for codeblock in &codeblocks {
            spans.push(hashed_regions::extract_marker_span(codeblock)?);
        }

        let (patch, cursor) = hashed_regions::build_patch_from_spans(
            prompt_inputs,
            &spans,
            Self::USER_CURSOR_MARKER,
        )?;

        let actual_cursor = cursor.map(|cursor| {
            ActualCursor::from_editable_region(
                &cursor.path,

View on GitHub (pinned to f4178619ac)

Solutions

1. Inspect the raw model response — it likely emitted prose or malformed fences instead of marker-bounded edits
2. Regenerate or re-prompt the teacher model to produce properly fenced edits

When it happens

Trigger: Thrown at crates/edit_prediction_cli/src/format_prompt.rs:430 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of zed-industries/zed@f4178619ac (2026-08-20). Data as JSON: /api/errors/d07e479791f8968d. Report an issue: GitHub.