react-native run-ios fails with "spawnSync xcrun ENOENT" on Windows

[Eyesonly88]

🐛 Bug Report

Doing react-native run-ios --device "Apple iPhone" from a Windows PC doesn't work.
I have my iPhone connected to my Windows PC but the command fails instantly with:
spawnSync xcrun ENOENT

To Reproduce

1. react-native init MyProject
2. yarn
3. react-native run-ios --device "Apple iPhone" from a Windows PC.

Expected Behavior

The hello world app is installed and running on the iPhone.

Code Example

I'm just using a brand new hello world without any code changes.

Error:

{ windowsIos }  » react-native run-ios --device "Apple iPhone" --verbose
(node:21384) ExperimentalWarning: The fs.promises API is experimental
Found Xcode project windowsIos.xcodeproj

spawnSync xcrun ENOENT

Error: spawnSync xcrun ENOENT
    at Object.spawnSync (internal/child_process.js:977:20)
    at spawnSync (child_process.js:581:24)
    at Object.execFileSync (child_process.js:609:13)
    at Object.runIOS [as func] (D:\ReactNative\windowsIosExperiment\windowsIos\node_modules\react-native\local-cli\runIOS\runIOS.js:76:17)
    at Promise.resolve.then (D:\ReactNative\windowsIosExperiment\windowsIos\node_modules\react-native\local-cli\cliEntry.js:117:22)

Environment

  React Native Environment Info:
    System:
      OS: Windows 10
      CPU: (8) x64 Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz
      Memory: 12.34 GB / 23.94 GB
    Binaries:
      Yarn: 1.2.1 - D:\Program Files (x86)\Yarn\bin\yarn.CMD
      npm: 5.6.0 - D:\Program Files\nodejs\npm.CMD

react-native-cli: 2.0.1
react-native: 0.58.4

If this is not supported, then the cli should make this more clear instead of actually trying to build and failing with errors.

[satya164]

You need XCode to build iOS apps. So it'll only work on a Mac and not on Windows. Pull request welcome to improve the error message though.