out, err := cmd.CombinedOutput()
			t.Logf("%v: %v", cmd, err)

			if uid != 0 && setgroups {
				t.Logf("as non-root, expected permission error due to unprivileged gid_map")
				if !os.IsPermission(err) {
					if err == nil {
						t.Skipf("unexpected success: probably old kernel without security fix?")
					}
					if testenv.SyscallIsNotSupported(err) {