go 版本升级到1.9.1 kcp 出问题

[stripluagio]

panic: reflect: call of reflect.Value.Int on zero Value

goroutine 9 [running]:
reflect.Value.Int(0x0, 0x0, 0x0, 0x174d146)
/usr/local/go/src/reflect/value.go:908 +0x141
agent/vendor/golang.org/x/net/ipv4.sysfd(0x1a8d440, 0xc42000e1a8, 0x136d8c8, 0xc420041e60, 0xc420041fa8)
/Users/apple/gamejob/gonet2/src/agent/vendor/golang.org/x/net/ipv4/helper_unix.go:46 +0x196
agent/vendor/golang.org/x/net/ipv4.(*genericOpt).sysfd(0xc420041ec0, 0x16a2de0, 0x172e8c0, 0x1)
/Users/apple/gamejob/gonet2/src/agent/vendor/golang.org/x/net/ipv4/helper_unix.go:17 +0x57
agent/vendor/golang.org/x/net/ipv4.(*genericOpt).SetTOS(0xc420041ec0, 0xb8, 0xc42000e1a8, 0x1a8d440)
/Users/apple/gamejob/gonet2/src/agent/vendor/golang.org/x/net/ipv4/genericopt_posix.go:29 +0x45
agent/vendor/github.com/xtaci/kcp-go.(*Listener).SetDSCP(0xc420114680, 0x2e, 0x0, 0x0)