if err == nil {
		log.Fatalf("expected cmd/link to fail")
	}

	firstLine := string(bytes.SplitN(out, []byte("\n"), 2)[0])
	if strings.HasPrefix(firstLine, "panic") {
		log.Fatalf("cmd/link panicked:\n%s", out)
	}

	if !strings.Contains(firstLine, message) {
		log.Fatalf("cmd/link output did not include expected message %q: %s", message, firstLine)
	}

	}

	if f, err := c.File(); err != nil {
		condFatalf(t, "file+net", "%v", err)
	} else {
		f.Close()
	}

	defer func() {
		if p := recover(); p != nil {
			t.Fatalf("panicked: %v", p)
		}
	}()

	c.WriteToUDP(wb, nil)
	c.WriteMsgUDP(wb, nil, nil)
}

func TestIPConnSpecificMethods(t *testing.T) {
	if !testableNetwork("ip4") {
		t.Skip("skipping: ip4 not supported")

		{true, s1, s2},
		{false, S4{[1000]byte{0}, func() {}}, S4{[1000]byte{1}, func() {}}},
	} {
		f := func() {
			defer func() {
				if recover() != nil {
					panic(fmt.Sprintf("comparing %#v and %#v panicked", test.a, test.b))
				}
			}()
			if test.a == test.b {
				panic(fmt.Sprintf("values %#v and %#v should not be equal", test.a, test.b))
			}
		}
		if test.panic {

	var p *Pool
	t.Run("Get", func(t *testing.T) {
		defer catch()
		if p.Get() != nil {
			t.Error("expected empty")
		}
		t.Error("should have panicked already")
	})
	t.Run("Put", func(t *testing.T) {
		defer catch()
		p.Put("a")
		t.Error("should have panicked already")
	})
}

func BenchmarkPool(b *testing.B) {
	var p Pool
	b.RunParallel(func(pb *testing.PB) {
		for pb.Next() {
			p.Put(1)

		// functions are correctly handled. This will smash
		// the stack frame but we're not going back there
		// anyway.
		if usesLR {
			c.savelr(c.lr())
		}

		// If PC == 0, probably panicked because of a call to a nil func.
		// Not faking that as the return address will make the trace look like a call
		// to sigpanic instead. (Otherwise the trace will end at
		// sigpanic and we won't get to see who faulted).

		// Call the debug function.
		h.debugCallRun(ctxt)
	case 1:
		// Function returned. Copy frame and result registers back out.
		h.debugCallReturn(ctxt)
	case 2:
		// Function panicked. Copy panic out.
		h.debugCallPanicOut(ctxt)
	case 8:
		// Call isn't safe. Get the reason.
		h.debugCallUnsafe(ctxt)
		// Don't wake h.done. We need to transition to status 16 first.
	case 16:

	if v != uint64(orig.Cur) {
		t.Errorf("exec rlimit = %d, want %d", v, orig)
	}
}

func TestForkExecNilArgv(t *testing.T) {
	defer func() {
		if p := recover(); p != nil {
			t.Fatal("forkExec panicked")
		}
	}()

	// We don't really care what the result of forkExec is, just that it doesn't
	// panic, so we choose something we know won't actually spawn a process (probably).

	}
	for _, tt := range tests {
		didPanic := make(chan bool)
		go func() {
			defer func() { didPanic <- recover() != nil }()
			tt.fn()
		}()
		if got := <-didPanic; got != tt.wantPanic {
			t.Errorf("%s: panicked = %v; want %v", tt.name, got, tt.wantPanic)
		}
	}
}

func TestBuilderWriteInvalidRune(t *testing.T) {
	// Invalid runes, including negative ones, should be written as
	// utf8.RuneError.