react-native run-ios不会启动应用程序

Question

每当我运行react-native run-ios时，它会在加载模拟器并输出

后挂起

Scanning 585 folders for symlinks in /Users/myname/Documents/Code/pma-game/node_modules (13ms)
Found Xcode workspace PMAGame.xcworkspace
Launching iPhone 6 (iOS 10.3)...
Building using "xcodebuild -workspace PMAGame.xcworkspace -configuration Debug -scheme PMAGame -destination id=3E2D26A0-B0FA-449C-B87C-EFB6BF2F25F1 -derivedDataPath build"
User defaults from command line:

    IDEDerivedDataPathOverride = /Users/myname/Documents/Code/pma-game/ios/build

我尝试过重启，但没有成功。我也尝试过重新安装反应原生和守望者。