plandex-ai/plandex · error

error mapping file %s: %v

Error message

error mapping file %s: %v

What it means

multi.go maps many files concurrently using a semaphore-bounded goroutine pool. Each file is run through MapFile (tree-sitter based structural mapping); any error returned by MapFile is wrapped as 'error mapping file %s: %v' and sent to the error channel. It indicates the per-file mapping step failed for that specific path.

Source

Thrown at app/server/syntax/file_map/multi.go:57

			mu.Lock()
			bodies[path] = "[NO MAP]"
			mu.Unlock()
			errCh <- nil
			continue
		} else if len(content) > shared.MaxContextMapSingleInputSize { // 1MB
			mu.Lock()
			bodies[path] = "[NO MAP - TOO LARGE]"
			mu.Unlock()
			errCh <- nil
			continue
		}

		sem <- struct{}{}
		go func(path, content string) {
			defer func() { <-sem }()
			fileMap, err := MapFile(ctx, path, []byte(content))
			if err != nil {
				errCh <- fmt.Errorf("error mapping file %s: %v", path, err)
				return
			}
			mu.Lock()
			defer mu.Unlock()
			bodies[path] = fileMap.String()
			errCh <- nil
		}(path, content)
	}

	for i := 0; i < len(inputs); i++ {
		err := <-errCh
		if err != nil {
			return nil, err
		}
	}

	return bodies, nil
}

View on GitHub (pinned to e2d772072e)

Solutions

1. Check the wrapped '%v' cause for the underlying MapFile failure
2. Confirm the file extension maps to a supported language/grammar
3. Exclude or skip unsupported files before calling the multi mapper
4. Update the syntax package/grammars if the language is expected to be supported

Example fix

// before
results, err := filemap.MultiMapFile(ctx, allPaths)
// after
for _, p := range allPaths {
    if parser, _, _, _ := syntax.GetParserForPath(p); parser == nil {
        log.Printf("skipping unsupported file: %s", p)
    }
}
results, err := filemap.MultiMapFile(ctx, supportedPaths)

parser, _, _, _ := syntax.GetParserForPath(path)
if parser == nil {
    return fmt.Errorf("no parser for %s, excluding from mapping", path)
}
if len(content) == 0 {
    return fmt.Errorf("empty file %s, excluding", path)
}

err := <-errCh
if err != nil && strings.HasPrefix(err.Error(), "error mapping file ") {
    var path string
    fmt.Sscanf(err.Error(), "error mapping file %s", &path)
    log.Printf("excluding failed file: %s", path)
}

When it happens

Trigger: MapFile(ctx, path, content) returns an error — typically an unsupported language/parser lookup failure or an internal parse failure for that file's content — during concurrent MultiMapFile processing.

Common situations: Batch-mapping a mixed-language codebase where some files have unrecognized extensions; empty or corrupted files; parser unavailable for a language on the installed tree-sitter grammars.

Related errors

• failed to parse file: %v
• failed to delete contexts: %v
• failed to read the file %s: %v
• error getting plan current branch: %v
• panic in UpdateContexts: %v\n%s

AI-assisted analysis of plandex-ai/plandex@e2d772072e (2026-09-05). Data as JSON: /api/errors/17abd511bc1a4000. Report an issue: GitHub.