plandex-ai/plandex · error

error validating original file syntax: %v

Error message

error validating original file syntax: %v

What it means

When a parser exists for the target file path, loadBuildFile validates the file's original (pre-build) syntax with syntax.ValidateWithParsers using the active plan context and the pre-build state. If that validation call itself errors (as opposed to reporting invalid syntax via validationRes.Valid), this error wraps and returns it. It indicates the syntax-validation machinery failed, not that the file is syntactically wrong.

Source

Thrown at app/server/model/plan/build_load.go:179

	planId := state.plan.Id
	branch := state.branch
	filePath := state.filePath

	activePlan := GetActivePlan(planId, branch)

	if activePlan == nil {
		return fmt.Errorf("active plan not found")
	}

	convoMessageId := activeBuild.ReplyId

	parser, lang, fallbackParser, fallbackLang := syntax.GetParserForPath(filePath)

	if parser != nil {
		validationRes, err := syntax.ValidateWithParsers(activePlan.Ctx, lang, parser, fallbackLang, fallbackParser, state.preBuildState)
		if err != nil {
			log.Printf(" error validating original file syntax: %v\n", err)
			return fmt.Errorf("error validating original file syntax: %v", err)
		}

		state.language = validationRes.Lang
		state.parser = validationRes.Parser

		state.builderRun.Lang = string(validationRes.Lang)

		if validationRes.TimedOut {
			state.syntaxCheckTimedOut = true
		} else if !validationRes.Valid {
			state.preBuildStateSyntaxInvalid = true
		}
	}

	build := &db.PlanBuild{
		OrgId:          currentOrgId,
		PlanId:         planId,
		ConvoMessageId: convoMessageId,

View on GitHub (pinned to e2d772072e)

Solutions

1. Read the underlying error logged just before this message to see whether it is a grammar load, file read, or context-cancel error.
2. Verify syntax.GetParserForPath returns the right parser for the file extension and that the grammar for that language is bundled/loaded.
3. Check the file exists and is readable (not deleted, not binary) before the build runs.
4. Increase the validation timeout / ensure activePlan.Ctx is not cancelled before validation completes.
5. Retry the build; if it reproduces on one file, isolate that file and report/fix the parser crash for that input.

Example fix

// before
validationRes, err := syntax.ValidateWithParsers(activePlan.Ctx, lang, parser, fallbackLang, fallbackParser, state.preBuildState)
if err != nil {
    return fmt.Errorf("error validating original file syntax: %v", err)
}
// after
if _, statErr := os.Stat(filePath); statErr != nil {
    return fmt.Errorf("file missing before syntax validation: %v", statErr)
}
validationRes, err := syntax.ValidateWithParsers(activePlan.Ctx, lang, parser, fallbackLang, fallbackParser, state.preBuildState)
if err != nil {
    log.Printf("syntax validation failed, continuing without validation: %v", err)
    validationRes = &syntax.ValidationResult{Valid: true, TimedOut: true}
}

parser, lang, fp, fl := syntax.GetParserForPath(filePath)
if parser == nil {
    return fmt.Errorf("no parser available for %s — syntax validation will be skipped", filePath)
}
if _, err := os.Stat(filePath); err != nil {
    return fmt.Errorf("file not readable before validation: %v", err)
}

func syntaxValidatable(parser syntax.Parser, ctx context.Context, preBuild *types.PreBuildState) bool {
    return parser != nil && ctx.Err() == nil && preBuild != nil
}

err := runPlanBuild(...)
if err != nil && strings.Contains(err.Error(), "error validating original file syntax") {
    log.Printf("syntax validation infrastructure failed (%v); proceeding without AST checks", err)
    // fall back to a build without syntax validation or surface a warning
}

When it happens

Trigger: syntax.ValidateWithParsers returns an error: the tree-sitter/AST parser fails to initialize or load grammar for the language, the file cannot be read or encoded, the pre-build state is nil/corrupt, the validation context (activePlan.Ctx) is cancelled/timed out, or the parser panics/crashes on malformed input.

Common situations: Unsupported or mis-detected language for the file extension; very large or binary files choking the parser; cancelled context after a long build; tree-sitter grammar version mismatch after a dependency upgrade; file deleted on disk between build scheduling and validation.

Related errors

• fast apply succeeded, but has %d syntax errors
• unsupported file type: %s
• failed to parse the content: %v
• failed to parse the content with fallback parser: %v
• invalid context index: %s

AI-assisted analysis of plandex-ai/plandex@e2d772072e (2026-09-05). Data as JSON: /api/errors/65cfa540e867696f. Report an issue: GitHub.