When running a WebKit debug build with shipping Safari, there is a crash-loop in Networking process: ASSERTION FAILED: m_sessionID.isEphemeral() || !path.isEmpty() /Users/ap/Safari/OpenSource/Source/WebKit/NetworkProcess/NetworkSession.cpp(646) : WebCore::SWServer &WebKit::NetworkSession::ensureSWServer() 1 0x1320dbb80 WTFCrash 2 0x114b3d284 WTFCrashWithInfo(int, char const*, char const*, int) 3 0x115ad4f1c WebKit::NetworkSession::ensureSWServer() 4 0x115961d2c WebKit::NetworkConnectionToWebProcess::establishSWServerConnection() 5 0x115961910 WebKit::NetworkConnectionToWebProcess::NetworkConnectionToWebProcess(WebKit::NetworkProcess&, WTF::ObjectIdentifier<WebCore::ProcessIdentifierType>, PAL::SessionID, IPC::Connection::Identifier) 6 0x11596165c WebKit::NetworkConnectionToWebProcess::NetworkConnectionToWebProcess(WebKit::NetworkProcess&, WTF::ObjectIdentifier<WebCore::ProcessIdentifierType>, PAL::SessionID, IPC::Connection::Identifier) 7 0x115961574 WebKit::NetworkConnectionToWebProcess::create(WebKit::NetworkProcess&, WTF::ObjectIdentifier<WebCore::ProcessIdentifierType>, PAL::SessionID, IPC::Connection::Identifier) 8 0x1159d7664 WebKit::NetworkProcess::createNetworkConnectionToWebProcess(WTF::ObjectIdentifier<WebCore::ProcessIdentifierType>, PAL::SessionID, WTF::CompletionHandler<void (std::__1::optional<WTF::MachSendRight>&&, WebCore::HTTPCookieAcceptPolicy)>&&)