plandex-ai/plandex · error

failed to parse the proposed content: %v

Error message

failed to parse the proposed content: %v

What it means

The counterpart of error 765: ExecApplyTreeSitter also parses the proposed (edited, comment-normalized) content. If that ParseCtx call fails, it returns 'failed to parse the proposed content: %v'. The proposed edit text itself could not be represented as a valid syntax tree for the chosen language.

Source

Thrown at app/server/syntax/structured_edits_tree_sitter.go:104

			}
		}
	}

	proposedWithNormalizedComments := strings.Join(proposedLines, "\n")
	res.Proposed = proposedWithNormalizedComments

	originalBytes := []byte(original)
	proposedBytes := []byte(proposedWithNormalizedComments)

	originalTree, err := parser.ParseCtx(ctx, nil, originalBytes)
	if err != nil {
		return nil, fmt.Errorf("failed to parse the original content: %v", err)
	}
	defer originalTree.Close()

	proposedTree, err := parser.ParseCtx(ctx, nil, proposedBytes)
	if err != nil {
		return nil, fmt.Errorf("failed to parse the proposed content: %v", err)
	}
	defer proposedTree.Close()

	if verboseLogging {
		fmt.Printf("anchorLines: %v\n", anchorLines)
	}

	oRes := BuildNodeIndex(originalTree)
	pRes := BuildNodeIndex(proposedTree)

	originalNodesByLineIndex := oRes.nodesByLine
	proposedNodesByLineIndex := pRes.nodesByLine
	originalParentsByLineIndex := oRes.parentsByLine

	findNextAnchor := func(s string, pLineNum int, pNode *tree_sitter.Node, fromLine int) *tsAnchor {
		oLineNum, ok := anchorLines[pLineNum]
		if ok {
			if verboseLogging {

View on GitHub (pinned to e2d772072e)

Solutions

1. Inspect the proposed content around the edit for syntax errors and regenerate/correct the edit
2. Validate the proposed snippet with ValidateWithParsers before applying
3. Ensure the correct language parser is selected for the file
4. Check the wrapped '%v' for timeout/cancellation and increase limits

Example fix

// before
res, err := edits.ApplyChanges(path, original, proposed)
// after
if vres, err := syntax.ValidateWithParsers(lang, proposed, parsers); err != nil || (vres != nil && vres.ParseHasError) {
    return fmt.Errorf("proposed edit invalid, skipping apply")
}
res, err := edits.ApplyChanges(path, original, proposed)

vres, err := syntax.ValidateWithParsers(lang, proposed, parsers)
if err != nil || vres == nil || vres.ParseHasError {
    return fmt.Errorf("proposed edit does not parse; regenerate")
}

func proposedEditParses(lang shared.Language, proposed string, parsers []*syntax.Parser) bool {
    res, err := syntax.ValidateWithParsers(lang, proposed, parsers)
    return err == nil && res != nil && !res.ParseHasError
}

res, err := ApplyChanges(path, original, proposed)
if err != nil && strings.Contains(err.Error(), "failed to parse the proposed content") {
    return retryWithCorrectedEdit(path, original, proposed) // ask model to fix syntax
}

When it happens

Trigger: The model/editor-generated proposedWithNormalizedComments text contains code invalid for the language, so tree-sitter's ParseCtx errors (or the context is cancelled/limit hit) during ApplyChanges → ExecApplyTreeSitter.

Common situations: LLM-proposed edits with malformed syntax or wrong-language snippets; normalization step corrupting code; wrong parser selected for the file; cancellation during long parses.

Understand the failure class

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• failed to parse the original content: %v
• failed to parse the content: %v
• error mapping file %s: %v
• failed to parse file: %v
• failed to parse the content with fallback parser: %v

AI-assisted analysis of plandex-ai/plandex@e2d772072e (2026-09-05). Data as JSON: /api/errors/c60311e99d52b8bb. Report an issue: GitHub.