// deletes it after the tests have been run.
func TestMain(m *testing.M) {
	// When CMDGO_TEST_RUN_MAIN is set, we're reusing the test binary as cmd/go.
	// Enable the special behavior needed in cmd/go/internal/work,
	// run the main func exported via export_test.go, and exit.
	// We set CMDGO_TEST_RUN_MAIN via os.Setenv and testScript.setup.
	if os.Getenv("CMDGO_TEST_RUN_MAIN") != "" {
		cfg.SetGOROOT(cfg.GOROOT, true)