gorootPath = runtime.GOROOT()
		if gorootPath != "" {
			return
		}

		// runtime.GOROOT is empty — perhaps go_android_exec was built with
		// -trimpath and GOROOT is unset. Try 'go env GOROOT' as a fallback,
		// assuming that the 'go' command in $PATH is the correct one.

		cmd := exec.Command("go", "env", "GOROOT")
		cmd.Stderr = os.Stderr
		out, err := cmd.Output()
		if err != nil {

package main

import (
	"fmt"
	"os"
)

func main() {
	if len(os.Args) != 2 {
		fatal("usage: callback testname")
	}
	switch os.Args[1] {
	default:
		fatal("unknown test %q", os.Args[1])
	case "Call":
		testCall()
	case "Callback":
		testCallback()
	}
	println("OK")
}

func fatal(f string, args ...any) {
	fmt.Fprintln(os.Stderr, fmt.Sprintf(f, args...))