golang/go · error

no files in package %s

Error message

no files in package %s

What it means

Thrown by `go tool export` (an internal helper driven by `go list -export`) inside readConfig, right after JSON-decoding the unit.cfg file. The config struct's GoFiles slice is empty, meaning the package has no Go source files to parse and type-check, so the exporter refuses to proceed and names cfg.ImportPath. The export tool is not intended to be invoked by end users; `go list -export` generates its config.

Source

Thrown at src/cmd/export/main.go:125

	}
	if err := gcexportdata.Write(f, fset, pkg); err != nil {
		f.Close() // ignore error
		return err
	}
	return f.Close()
}

func readConfig(filename string) (*config, error) {
	data, err := os.ReadFile(filename)
	if err != nil {
		return nil, err
	}
	cfg := new(config)
	if err := json.Unmarshal(data, cfg); err != nil {
		return nil, fmt.Errorf("can't decode input %s: %v", filename, err)
	}
	if len(cfg.GoFiles) == 0 {
		return nil, fmt.Errorf("no files in package %s", cfg.ImportPath)
	}
	return cfg, nil
}

func makeTypesImporter(cfg *config, fset *token.FileSet) types.Importer {
	imports := make(map[string]*types.Package)
	imports["unsafe"] = types.Unsafe
	return importerFunc(func(importPath string) (*types.Package, error) {
		pkgPath, ok := cfg.ImportMap[importPath]
		if !ok {
			return nil, fmt.Errorf("can't resolve import %s", importPath)
		}
		// Check for cache hit.
		if pkg, ok := imports[pkgPath]; ok && pkg.Complete() {
			return pkg, nil
		}
		// Miss.
		cfgPath, ok := cfg.PackageFile[pkgPath]

View on GitHub (pinned to b6b368adc5)

Solutions

1. Do not call `go tool export` directly; run `go list -export <pkg>` which generates a correct config including GoFiles.
2. If you must supply a config, ensure cfg.GoFiles contains at least one absolute path to a .go file that belongs to the package.
3. Confirm the package actually has Go source files for your GOOS/GOARCH (run `go list -f '{{.GoFiles}}' <pkg>`).
4. Re-run `go list -export` after any source/build-context change to regenerate the config.

// Before passing a config to export, verify it has source files.
if len(cfg.GoFiles) == 0 {
    return fmt.Errorf("config for %s has no Go files; regenerate via 'go list -export'", cfg.ImportPath)
}

When it happens

Trigger: A unit.cfg with a GoFiles array of length zero is passed to `go tool export`. This occurs when the package being exported contains no .go files for the active build context (e.g. an assembly-only package, or all .go files excluded by build tags), or when a hand-written config omits GoFiles.

Common situations: Running `go tool export unit.cfg` directly on a hand-authored config; building a package composed solely of .s assembly or cgo .c/.h files with no .go files; GOOS/GOARCH build constraints filtering out every Go file; a stale or corrupted config produced by an interrupted `go list -export`.

Related errors

• can't decode input %s: %v
• can't resolve import %s
• can't resolve export %s
• cannot run go list: %v %s
• decoding go list json: %v

AI-assisted analysis of golang/go@b6b368adc5 (2026-08-12). Data as JSON: /api/errors/58de8398fd91ed57. Report an issue: GitHub.