syscall: fix TestGroupCleanup{UserNamespace} on Alpine

This updates TestGroupCleanup and TestGroupCleanupUserNamespace to pass in the
Alpine builder.

Updates #19938

Change-Id: Iacbfd73782eccd57f872f9e85726c6024529c277
Reviewed-on: https://go-review.googlesource.com/40692
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>

diff --git a/src/syscall/exec_linux_test.go b/src/syscall/exec_linux_test.go
index 9551e7ec716d03b24b34b5fafa25e4f9d0076073..83cde96b1fab99cbb6d8320cec6620c7f6497395 100644 (file)
--- a/src/syscall/exec_linux_test.go
+++ b/src/syscall/exec_linux_test.go
@@ -207,9 +207,10 @@ func TestGroupCleanup(t *testing.T) {
                t.Fatalf("Cmd failed with err %v, output: %s", err, out)
        }
        strOut := strings.TrimSpace(string(out))
-       expected := "uid=0(root) gid=0(root) groups=0(root)"
+       expected := "uid=0(root) gid=0(root)"
        // Just check prefix because some distros reportedly output a
        // context parameter; see https://golang.org/issue/16224.
+       // Alpine does not output groups; see https://golang.org/issue/19938.
        if !strings.HasPrefix(strOut, expected) {
                t.Errorf("id command output: %q, expected prefix: %q", strOut, expected)
        }
@@ -247,6 +248,7 @@ func TestGroupCleanupUserNamespace(t *testing.T) {
                "uid=0(root) gid=0(root) groups=0(root),65534(nobody)",
                "uid=0(root) gid=0(root) groups=0(root),65534(nogroup)",
                "uid=0(root) gid=0(root) groups=0(root),65534",
+               "uid=0(root) gid=0(root) groups=0(root),65534(nobody),65534(nobody),65534(nobody),65534(nobody),65534(nobody),65534(nobody),65534(nobody),65534(nobody),65534(nobody),65534(nobody)", // Alpine; see https://golang.org/issue/19938
        }
        for _, e := range expected {
                if strOut == e {