syscall: deflake TestUnshare

Change-Id: I21a08c2ff5ebb74e158723cca323574432870ba8
Reviewed-on: https://go-review.googlesource.com/23662
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

diff --git a/src/syscall/exec_linux_test.go b/src/syscall/exec_linux_test.go
index 1afe88cb1bab0377a70c2fff15110f1f268ac218..a562c9cbf2ae6ed1e4dbc06e2239192edb2e7e79 100644 (file)
--- a/src/syscall/exec_linux_test.go
+++ b/src/syscall/exec_linux_test.go
@@ -145,7 +145,18 @@ func TestUnshare(t *testing.T) {
                t.Skip("skipping test on Kubernetes-based builders; see Issue 12815")
        }
 
-       cmd := exec.Command("cat", "/proc/net/dev")
+       path := "/proc/net/dev"
+       if _, err := os.Stat(path); err != nil {
+               if os.IsNotExist(err) {
+                       t.Skip("kernel doesn't support proc filesystem")
+               }
+               if os.IsPermission(err) {
+                       t.Skip("unable to test proc filesystem due to permissions")
+               }
+               t.Fatal(err)
+       }
+
+       cmd := exec.Command("cat", path)
        cmd.SysProcAttr = &syscall.SysProcAttr{
                Unshareflags: syscall.CLONE_NEWNET,
        }