I cant get my ionic app to open in iOS emulator - xcode

Question

My new ionic app won't run in the iOS emulator.
Its a fresh install of ionic and Xcode, these are my steps:
npm install -g ionic
ionic start myApp tabs
ionic cordova platform add ios
ionic cordova build ios
ionic cordova emulate ios
Then I get the following error:
No target specified for emulator. Deploying to undefined simulator
/localhost/myApp/platforms/ios/build/emulator/MyApp.app/Info.plist
file not found.
According to this thread (Fresh Ionic Fails to Emulate iOS 12 - Info.plist file not found) it should work with the following command:
ionic cordova emulate ios -- --buildFlag="-UseModernBuildSystem=0"
But then I get the following error:
No target specified for emulator. Deploying to undefined simulator
Device type "com.apple.CoreSimulator.SimDeviceType.undefined" could not be found.
And then according to this thread (Issues starting iOS simulator from CLI) it should work by updating ios-sim like this:
cd platforms/ios/cordova && npm install ios-sim#latest
But I still get the following error:
No target specified for emulator. Deploying to undefined simulator
Device type "com.apple.CoreSimulator.SimDeviceType.undefined" could not be found.
Ionic:
ionic (Ionic CLI) : 4.10.2 (/usr/local/lib/node_modules/ionic)
Ionic Framework : #ionic/angular 4.0.1
#angular-devkit/build-angular : 0.12.4
#angular-devkit/schematics : 7.2.4
#angular/cli : 7.2.4
#ionic/angular-toolkit : 1.4.0
Cordova:
cordova (Cordova CLI) : 8.1.2 (cordova-lib#8.1.1)
Cordova Platforms : ios 4.5.0
Cordova Plugins : cordova-plugin-ionic-keyboard 2.1.3, cordova-plugin-ionic-webview 3.1.2, (and 4 other plugins)
System:
ios-deploy : 1.9.4
ios-sim : 7.0.0
NodeJS : v10.15.1 (/usr/local/bin/node)
npm : 6.4.1
OS : macOS Mojave
Xcode : Xcode 10.1 Build version 10B61

Answer 1

The problem lie with ios-sim package which couldn't detect running simulators.
Updating to 8.0.1 with the following steps resolved the issue for me.
force update ios-sim to a working version
IMPORTANT needs to be done from inside the platforms/ios/cordova directory.
cd platforms/ios/cordova && npm install ios-sim#8.0.1
check if devices are now listed, takes a few seconds
ionic cordova emulate --list
installs appscript if not installed already
ionic cordova build ios
try to deploy to simulator
ionic cordova emulate --release --prod --livereload ios -- --buildFlag="-UseModernBuildSystem=0"
This will find any running simulator and deploy the app

Answer 2

Try just building the project and then running it from Xcode instead first.
ionic cordova build ios -- --buildFlag="-UseModernBuildSystem=0"
Then open the platforms/ios folder in Xcode and you'll be able to run it from there plus see any errors there may be with the project. When you eventually decide to push the app to the store you'll need to do this anyway.
EDIT
Then try targeting a specific emulator:
ionic cordova emulate ios --list get list of available targets to copy into the next command.
ionic cordova emulate --livereload ios -- --buildFlag="-UseModernBuildSystem=0" --target="iPhone-X, 12.1" example targeting iPhone XR.

Answer 3

The issue is related to a breaking changes on Xcode 10 not already reflected on ios-sim. You can check on ion-sim repo issue "List empty of devices simulator with Xcode 10".
The issue have already been fixed but is waiting for a new release submission.
You can continue running your App on emulator directly from Xcode.