os.Setenv("GODEBUG", os.Getenv("GODEBUG")+reducedLimit)
	}

	// Don't let these environment variables confuse the test.
	os.Setenv("GOENV", "off")
	os.Unsetenv("GOFLAGS")
	os.Unsetenv("GOBIN")
	os.Unsetenv("GOPATH")
	os.Unsetenv("GIT_ALLOW_PROTOCOL")
	os.Setenv("HOME", "/test-go-home-does-not-exist")
	// On some systems the default C compiler is ccache.
	// Setting HOME to a non-existent directory will break

	// always go to GOROOT/bin anyway.
	os.Setenv("GOBIN", gorootBin)

	// Make the environment more predictable.
	os.Setenv("LANG", "C")
	os.Setenv("LANGUAGE", "en_US.UTF8")
	os.Unsetenv("GO111MODULE")
	os.Setenv("GOENV", "off")
	os.Unsetenv("GOFLAGS")
	os.Setenv("GOWORK", "off")

	workdir = xworkdir()
	if err := os.WriteFile(pathf("%s/go.mod", workdir), []byte("module bootstrap"), 0666); err != nil {

	}

	setupCmd = func(cmd *exec.Cmd) {
		setDir(cmd, filepath.Join(goroot, "src"))
		if len(opts.env) != 0 {
			for _, kv := range opts.env {
				if i := strings.Index(kv, "="); i < 0 {
					unsetEnv(cmd, kv[:len(kv)-1])
				} else {
					setEnv(cmd, kv[:i], kv[i+1:])
				}
			}
		}
		if runOnHost {
			setEnv(cmd, "GOARCH", gohostarch)
			setEnv(cmd, "GOOS", gohostos)
		}
	}

	// disable ENVs which interfere with tests.
	for _, env := range []string{
		crypto.EnvKMSAutoEncryption,
		config.EnvAccessKey,
		config.EnvSecretKey,
		config.EnvRootUser,
		config.EnvRootPassword,
	} {
		os.Unsetenv(env)
	}

	// Set as non-distributed.
	globalIsDistErasure = false

	// Disable printing console messages during tests.
	color.Output = io.Discard
	// Disable Error logging in testing.

		c.Fatalf("cannot set environment variable: %v", err)
	}

	if ok {
		c.Cleanup(func() {
			os.Setenv(key, prevValue)
		})
	} else {
		c.Cleanup(func() {
			os.Unsetenv(key)
		})
	}
}

// panicHandling controls the panic handling used by runCleanup.
type panicHandling int

const (
	normalPanic panicHandling = iota
	recoverAndReturnPanic
)