func (rp *IndexPackage) ScanDir(tags map[string]bool) (sortedImports []string, sortedTestImports []string, err error) {
	// TODO(matloob) dir should eventually be relative to indexed directory
	// TODO(matloob): skip reading raw package and jump straight to data we need?

	defer func() {
		if e := recover(); e != nil {
			err = fmt.Errorf("error reading module index: %v", e)
		}
	}()

}

func (n *node) isDir() bool {
	return n.actualFilePath == "" && n.children != nil
}

func (n *node) isDeleted() bool {
	return n.actualFilePath == "" && n.children == nil
}

// TODO(matloob): encapsulate these in an io/fs-like interface
var overlay map[string]*node // path -> file or directory node
var cwd string               // copy of base.Cwd() to avoid dependency

	buildVersion := buildcfg.Version
	if goexperiment := buildcfg.Experiment.String(); goexperiment != "" {
		buildVersion += " X:" + goexperiment
	}
	addstrdata1(ctxt, "runtime.buildVersion="+buildVersion)

	// TODO(matloob): define these above and then check flag values here
	if ctxt.Arch.Family == sys.AMD64 && buildcfg.GOOS == "plan9" {
		flag.BoolVar(&flag8, "8", false, "use 64-bit addresses in symbol table")
	}

	// to the path the disk path would be rewritten to.

	cgoFiles := make(map[string]bool)
	for _, f := range a.Package.CgoFiles {
		cgoFiles[f] = true
	}

	// TODO(matloob): Higher up in the stack, when the logic for deciding when to make copies
	// of c/c++/m/f/hfiles is consolidated, use the same logic that Build uses to determine

	// cache is being served by a GOPROXY HTTP server. This will be corrected
	// the next time a new version of the module is fetched and the file is rewritten.
	// TODO(matloob): golang.org/issue/43313 covers adding a go mod verify
	// command that removes module versions that fail checksums. It should also
	// remove list files that are detected to be corrupt.
	f, err := lockedfile.Edit(listFile)