xcode command line test with argument passed at launch
xcodebuild is for build your app. You can use this command to run your app with specific language.
xcrun simctl launch <deviceid> <appid> -AppleLanguages "(pt-BR)"Hera a sample with all steps to buil and run your app:
xcodebuild -sdk iphonesimulator8.4 -arch i386 install DSTROOT=YourAppFolderxcrun instruments -w "iPhone 6 (8.4 Simulator)"xcrun simctl install booted YourAppFolder/Applications/YourApp.appxcrun simctl launch booted com.yourdomain.yourapp -AppleLanguages "(pt-BR)"