// walking the tree and copying it piecewise. If the directory tree
			// contains nested modules this could push a lot of unnecessary contents,
			// but for the golang.org/x repos it seems to be significantly (~2x)
			// faster than copying one file at a time (via filepath.WalkDir),
			// apparently due to high latency in 'adb' commands.
			if err := adb("push", modDir, deviceModDir); err != nil {

	}

	name := contextName(w.context)

	imports, ok := listCache.Load(name)
	if !ok {
		listSem <- semToken{}
		defer func() { <-listSem }()

		cmd := exec.Command(goCmd(), "list", "-e", "-deps", "-json", "std")
		cmd.Env = listEnv(w.context)
		if w.context.Dir != "" {
			cmd.Dir = w.context.Dir
		}
		cmd.Stderr = os.Stderr
		out, err := cmd.Output()
		if err != nil {