| // Copyright 2015 The Go Authors. All rights reserved. | 
 | // Use of this source code is governed by a BSD-style | 
 | // license that can be found in the LICENSE file. | 
 |  | 
 | package runtime_test | 
 |  | 
 | import ( | 
 | 	"runtime" | 
 | 	"syscall" | 
 | 	"testing" | 
 | ) | 
 |  | 
 | func TestFixedGOROOT(t *testing.T) { | 
 | 	if runtime.GOOS == "plan9" { | 
 | 		t.Skipf("skipping plan9, it is inconsistent by allowing GOROOT to be updated by Setenv") | 
 | 	} | 
 |  | 
 | 	// Restore both the real GOROOT environment variable, and runtime's copies: | 
 | 	if orig, ok := syscall.Getenv("GOROOT"); ok { | 
 | 		defer syscall.Setenv("GOROOT", orig) | 
 | 	} else { | 
 | 		defer syscall.Unsetenv("GOROOT") | 
 | 	} | 
 | 	envs := runtime.Envs() | 
 | 	oldenvs := append([]string{}, envs...) | 
 | 	defer runtime.SetEnvs(oldenvs) | 
 |  | 
 | 	// attempt to reuse existing envs backing array. | 
 | 	want := runtime.GOROOT() | 
 | 	runtime.SetEnvs(append(envs[:0], "GOROOT="+want)) | 
 |  | 
 | 	if got := runtime.GOROOT(); got != want { | 
 | 		t.Errorf(`initial runtime.GOROOT()=%q, want %q`, got, want) | 
 | 	} | 
 | 	if err := syscall.Setenv("GOROOT", "/os"); err != nil { | 
 | 		t.Fatal(err) | 
 | 	} | 
 | 	if got := runtime.GOROOT(); got != want { | 
 | 		t.Errorf(`after setenv runtime.GOROOT()=%q, want %q`, got, want) | 
 | 	} | 
 | 	if err := syscall.Unsetenv("GOROOT"); err != nil { | 
 | 		t.Fatal(err) | 
 | 	} | 
 | 	if got := runtime.GOROOT(); got != want { | 
 | 		t.Errorf(`after unsetenv runtime.GOROOT()=%q, want %q`, got, want) | 
 | 	} | 
 | } |