swift crash when getcurrentip address : FixedWidthInteger.init<A>

问题

I found this bug when tried to get ip address through wifi. After install fabric, i got this error

0  MY_APP                      0x1020e538c specialized FixedWidthInteger.init<A>(_:radix:)
 (My_Screen.swift)

After find the method error, i found this line :

if addrFamily == UInt8(AF_INET) || addrFamily == UInt8(AF_INET6) linked to FixedWidthInteger:

public struct UInt8 : FixedWidthInteger, UnsignedInteger

I dont know why this problem triggered. can some one help?

Here i my full code to get currentIp address

func getIPAddress() -> String? {
        var address: String?
        var ifaddr: UnsafeMutablePointer<ifaddrs>? = nil
        if getifaddrs(&ifaddr) == 0 {
            var ptr = ifaddr
            while ptr != nil {
                defer { ptr = ptr?.pointee.ifa_next }

                let interface = ptr?.pointee
                let addrFamily = interface?.ifa_addr.pointee.sa_family
                if addrFamily == UInt8(AF_INET) || addrFamily == UInt8(AF_INET6) {

                    if let name = String(cString: (interface?.ifa_name)!) as String?, name == "en0" {
                        var hostname = [CChar](repeating: 0, count: Int(NI_MAXHOST))
                        getnameinfo(interface?.ifa_addr, socklen_t((interface?.ifa_addr.pointee.sa_len)!), &hostname, socklen_t(hostname.count), nil, socklen_t(0), NI_NUMERICHOST)
                        address = String(cString: hostname)
                    }
                }
            }
            freeifaddrs(ifaddr)
        }
        return address
    }

UPDATE NOTE: I have 4 devices ios 12.1 + 1 device ios 12.2, only 1 device ios 12.1 + ios device 12.2 crash, 3 other devices work normally.

来源：https://stackoverflow.com/questions/55491986/swift-crash-when-getcurrentip-address-fixedwidthinteger-inita