React Native: XCode: Build failed with error "EMFILE: too many open files, watch"

Question

– MackBook Air M1 – macOS 11.3 – XCode 12.5 – react native 0.64.1 – node 16.0.0 – npm 7.15.1 – watchman 2021.05.31.00

When I try to archive a project or build one for a device, Xcode stops building with an error:

/Users/aptyp/Projects/Proffmylife/Client/node_modules/metro-hermes-compiler/src/emhermesc.js:81
          throw ex;
          ^

Error: EMFILE: too many open files, watch
    at FSEvent.FSWatcher._handle.onchange (node:internal/fs/watchers:204:21)
Emitted 'error' event on NodeWatcher instance at:
    at NodeWatcher.checkedEmitError (/Users/aptyp/Projects/Proffmylife/Client/node_modules/sane/src/node_watcher.js:143:12)
    at FSWatcher.emit (node:events:365:28)
    at FSEvent.FSWatcher._handle.onchange (node:internal/fs/watchers:210:12) {
  errno: -24,
  syscall: 'watch',
  code: 'EMFILE',
  filename: null
}
Command PhaseScriptExecution failed with a nonzero exit code

But for the simulator, the build works fine.

I have tried to reinstall node_modules, Pods, watchman with brew. Also I've created files limit.maxfiles.plist, limit.maxproc.plist into dir /Library/LaunchDaemons/ and now ulimit -a shows processes 2000 and file descriptors 524288. Restarting computer and unlock Keychain.

On my PC with Hackintosh I don't have this problem.

Answer 1

This error is because of a bug in module fsevents for mac m1 silicon. See the thread: https://github.com/facebook/metro/issues/668

It got fixed with new version of watchman. Upgrade your watchman through brew. Delete your project and download from git and rebuild everything along with pod install and then it should archive no problem.

Facebook guy admitting to the bug and fixing it