After updating xcode 'ionic build ios' not working

**Description:**
I have updated my Xcode v9.0 to v10.0. after updating Xcode `ionic build ios` does not work anymore, therefore `ionic emulate ios` doesn't work, meaning I cannot run the app through the ionic CLI but I am able to run an app through Xcode.

`ionic build android` still works fine.

**Output:**
'ionic emulate ios' gives an error as:
No target specified for emulator. Deploying to iPhone-XS-Max, 12.0 simulator
/Users/.../mobileApp/platforms/ios/build/emulator/demo APP.app/Info.plist file not found.
[ERROR] An error occurred while running subprocess cordova.

cordova emulate ios exited with exit code 1.

**My `ionic info`:**
Ionic:

ionic (Ionic CLI) : 4.1.2 (/Users/tanvishah/.nvm/versions/node/v10.5.0/lib/node_modules/ionic)
Ionic Framework : ionic-angular 3.7.1
@ionic/app-scripts : 3.0.1

Cordova:

cordova (Cordova CLI) : 8.0.0
Cordova Platforms : android 7.0.0, ios 4.5.5
Cordova Plugins : cordova-plugin-ionic-webview 1.2.1, (and 11 other plugins)

System:

Android SDK Tools : 26.1.1 (/Users/xyz/Library/Android/sdk)
ios-deploy : 2.0.0
NodeJS : v10.5.0 (/Users/xyz/.nvm/versions/node/v10.5.0/bin/node)
npm : 6.1.0
OS : macOS High Sierra
Xcode : Xcode 10.0 Build version 10A255