I`m trying create simple http sever, when I do it in main target of my macOS app then it works, but when I do it in uitests target it fails (result == -1 (Operation not permitted)). Interestingly when I run it in iOS uiTests target then it works. let sockfd = socket(AF_INET, SOCK_STREAM, 0) var serverAddress = sockaddr_in(sin_len: __uint8_t(MemoryLayout<sockaddr_in>.size), sin_family: sa_family_t(AF_INET), sin_port: CFSwapInt16HostToBig(8080), sin_addr: in_addr(s_addr: inet_addr("127.0.0.1")), sin_zero: (0, 0, 0, 0, 0, 0, 0, 0)) let result = withUnsafePointer(to: &serverAddress) { $0.withMemoryRebound(to: sockaddr.self, capacity: 1) { Darwin.bind(sockfd, $0, socklen_t(MemoryLayout<sockaddr_in>.size)) } } I've got set in my main target entitlements: <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"> <plist version="1.0"> <dict> <key>com.apple.security.app-sandbox</key> <true/> <key>com.apple.security.network.client</key> <true/> <key>com.apple.security.network.server</key> <true/> </dict> </plist> What can be reason that it fails? how can I fix it?