While working on a React Native project, I encountered a frustrating error that prevented my app from running on iOS. The error log is as follows:
bkpandey@Balkrishnas-MacBook-Pro medvisor % npm run ios
> [email protected] ios
> expo start --ios
Starting project at /Users/bkpandey/Documents/workspace/code/dmeo/medvisor
Starting Metro Bundler
βΊ Opening exp://192.168.7.243:8081 on iPhone 12
β ¦ Fetching Expo Gonode:events:497
throw er; // Unhandled 'error' event
^
Error: EMFILE: too many open files, watch
at FSEvent.FSWatcher._handle.onchange (node:internal/fs/watchers:207:21)
Emitted 'error' event on NodeWatcher instance at:
at FSWatcher._checkedEmitError (/Users/bkpandey/Documents/workspace/code/dmeo/medvisor/node_modules/metro-file-map/src/watchers/NodeWatcher.js:82:12)
at FSWatcher.emit (node:events:519:28)
at FSEvent.FSWatcher._handle.onchange (node:internal/fs/watchers:213:12) {
errno: -24,
syscall: 'watch',
code: 'EMFILE',
filename: null
}
Node.js v20.14.0
Understanding the EMFILE Error
The EMFILE
error occurs when the system exceeds the maximum number of file descriptors it can open simultaneously. This is a common issue in large projects with many files.
Introducing Watchman
Watchman is a tool developed by Facebook for watching changes in the filesystem. It is designed to handle large codebases efficiently and helps in avoiding the EMFILE
error by optimizing the way file changes are monitored.
Resolving the Issue with Watchman
To resolve the EMFILE
error, you can install Watchman, which Metro (the JavaScript bundler for React Native) can utilize to manage file watching more efficiently.
Installation
To install Watchman on macOS, use Homebrew:
brew install watchman
Try running the project again the issue disappeared magically!
npm run ios
Top comments (0)