Leon Chaewon Kong's dev blog

React Native - iOS Error: Could not parse the simulator list output.

Environments Version
react-native 0.60.4
Xcode 11.2

Recently, I updated Xcode from 11.1 to 11.2 and faced error like:

info Found Xcode workspace "Native_Makkcha.xcworkspace"
2019-11-12 11:55:22.239 simctl[12139:74526] CoreSimulator detected version change.  Framework version (681.15) does not match existing job version (681.5.4).  Attempting to remove the stale service in order to add the expected version.
error Could not parse the simulator list output. Run CLI with --verbose flag for more details.
SyntaxError: Unexpected token I in JSON at position 0
    at JSON.parse (<anonymous>)
    at runOnSimulator (/Users/leonkong/Desktop/dev/CodingHippo/Native_Makkcha/node_modules/@react-native-community/cli-platform-ios/build/commands/runIOS/index.js:128:23)
    at Object.runIOS [as func] (/Users/leonkong/Desktop/dev/CodingHippo/Native_Makkcha/node_modules/@react-native-community/cli-platform-ios/build/commands/runIOS/index.js:97:12)
    at Command.handleAction (/Users/leonkong/Desktop/dev/CodingHippo/Native_Makkcha/node_modules/@react-native-community/cli/build/cliEntry.js:160:21)
    at Command.listener (/Users/leonkong/Desktop/dev/CodingHippo/Native_Makkcha/node_modules/commander/index.js:315:8)
    at Command.emit (events.js:198:13)
    at Command.parseArgs (/Users/leonkong/Desktop/dev/CodingHippo/Native_Makkcha/node_modules/commander/index.js:651:12)
    at Command.parse (/Users/leonkong/Desktop/dev/CodingHippo/Native_Makkcha/node_modules/commander/index.js:474:21)
    at setupAndRun (/Users/leonkong/Desktop/dev/CodingHippo/Native_Makkcha/node_modules/@react-native-community/cli/build/cliEntry.js:210:24)
    at Object.run (/Users/leonkong/Desktop/dev/CodingHippo/Native_Makkcha/node_modules/@react-native-community/cli/build/cliEntry.js:173:11)


Solution is simple. Just open up [YourProjectName].xcworkspace file, then Xcode will automatically install some components.

My error disappeared automatically.

Possible Error

After opening up my .xcworkspace file, Could not parse the simulator list output error finally disappeared.

Yet, I encountered another error:

info Found Xcode workspace "Native_Makkcha.xcworkspace"
error Could not find "iPhone X" simulator. Run CLI with --verbose flag for more details.

This error has occured since Xcode ver. 11.1 because of mis-match of React Native’s target build device and Xcode’s device name.

You can see detail here: React Native - Could Not Find ‘iPhone X’ Error

So, I manually added “iPhone X” in Xcode. Here’s how:

See “+” button in left bottom corner? Press the button and just add “iPhone X” like picture before.