}

	errs = AppendErr(errs, nil)
	if got, want := errs.String(), ""; got != want {
		t.Errorf("got: %s, want: %s", got, want)
	}

	errs = AppendErr(errs, fmt.Errorf("err1"))
	if got, want := errs.String(), "err1"; got != want {
		t.Errorf("got: %s, want: %s", got, want)
	}

	errs = AppendErr(errs, nil)
	errs = AppendErr(errs, fmt.Errorf("err2"))
	if got, want := errs.String(), "err1, err2"; got != want {

		}
		if !cred.NoSetGroups {
			_, _, err1 = RawSyscall(SYS_SETGROUPS, ngroups, groups, 0)
			if err1 != 0 {
				goto childerror
			}
		}
		_, _, err1 = RawSyscall(SYS_SETGID, uintptr(cred.Gid), 0, 0)
		if err1 != 0 {
			goto childerror
		}
		_, _, err1 = RawSyscall(SYS_SETUID, uintptr(cred.Uid), 0, 0)
		if err1 != 0 {
			goto childerror
		}
	}

	// Chdir

	const name, id = "bimmler", 17
	err := fmt.Errorf("user %q (id %d) not found", name, id)
	if err != nil {
		fmt.Print(err)
	}
	// Output: user "bimmler" (id 17) not found
}

func ExampleJoin() {
	err1 := errors.New("err1")
	err2 := errors.New("err2")
	err := errors.Join(err1, err2)
	fmt.Println(err)
	if errors.Is(err, err1) {
		fmt.Println("err is err1")
	}
	if errors.Is(err, err2) {

	for {
		n, err = readlen(p[0], (*byte)(unsafe.Pointer(&err1)), int(unsafe.Sizeof(err1)))
		if err != EINTR {
			break
		}
	}
	Close(p[0])
	if err != nil || n != 0 {
		if n == int(unsafe.Sizeof(err1)) {
			err = Errno(err1)
		}
		if err == nil {
			err = EPIPE
		}

		// Child failed; wait for it to exit, to make sure
		// the zombies don't accumulate.
		_, err1 := Wait4(pid, &wstatus, 0, nil)

		}
		if !cred.NoSetGroups {
			err1 = setgroups1(ngroups, groups)
			if err1 != 0 {
				goto childerror
			}
		}
		err1 = setgid(uintptr(cred.Gid))
		if err1 != 0 {
			goto childerror
		}
		err1 = setuid(uintptr(cred.Uid))
		if err1 != 0 {
			goto childerror
		}
	}

	// Chdir
	if dir != nil {
		err1 = chdir(uintptr(unsafe.Pointer(dir)))
		if err1 != 0 {

			return 0, false
		}
		e, err1 := strconv.Atoi(exp)
		if err1 != nil {
			println("bad p", exp)
			return 0, false
		}
		return float32(float64(n) * pow2(e)), true
	}
	f64, err1 := strconv.ParseFloat(s, 32)
	f1 := float32(f64)
	if err1 != nil {
		return 0, false
	}
	return f1, true
}

func TestFp(t *testing.T) {
	f, err := os.Open("testdata/testfp.txt")
	if err != nil {

	for i, irs := range invalidRangeSpecs {
		var err1, err2 error
		var rs *HTTPRangeSpec
		var o, l int64
		rs, err1 = parseRequestRangeSpec(irs)
		if err1 == nil {
			o, l, err2 = rs.GetOffsetLength(resourceSize)
		}
		if isErrInvalidRange(err1) || (err1 == nil && isErrInvalidRange(err2)) {
			continue
		}
		t.Errorf("Case %d: Expected errInvalidRange but: %v %v %d %d %v", i, rs, err1, o, l, err2)
	}
}

		}
		return err
	}

	// Remove contents & return first error.
	err = nil
	for {
		names, err1 := fd.Readdirnames(100)
		for _, name := range names {
			err1 := RemoveAllOneFilesystemCommon(mounter, path+string(os.PathSeparator)+name, remove)
			if err == nil {
				err = err1
			}
		}
		if err1 == io.EOF {
			break
		}
		// If Readdirnames returned an error, use it.
		if err == nil {
			err = err1
		}

	pos, err := f.Seek(0, io.SeekCurrent)
	if err != nil {
		return 0, err, false
	}

	sc, err := f.SyscallConn()
	if err != nil {
		return 0, nil, false
	}

	var werr error
	err = sc.Read(func(fd uintptr) bool {
		written, werr, handled = poll.SendFile(&c.pfd, int(fd), pos, remain)
		return true
	})
	if err == nil {
		err = werr
	}

	if lr != nil {

	if err1 != 0 {
		t.Fatalf("jail_set: %v", err1)
	}
	t.Cleanup(func() {
		_, _, err1 := syscall.Syscall(syscall.SYS_JAIL_REMOVE, id, 0, 0)
		if err1 != 0 {
			t.Errorf("failed to cleanup jail: %v", err)
		}
	})

	return int(id), root
}

func TestJailAttach(t *testing.T) {
	if os.Getenv("GO_WANT_HELPER_PROCESS") == "1" {
		jailed, err := syscall.SysctlUint32("security.jail.jailed")
		if err != nil {