Why "Watchman crawl failed" error in react-native immediately after updating to macOS catalina?

Trying to run react-native run-ios or build RN project from xcode, as soon as metro bundler starts, this error appears in the terminal:

Loading dependency graph...jest-haste-map: Watchman crawl failed. Retrying once with node crawler.
  Usually this happens when watchman isn't running. Create an empty `.watchmanconfig` file in your project's root folder or initialize a git or hg repository in your project.
  Error: Watchman error: resolve_projpath: path `/Users/vorousjames/Desktop/Development/TicTacWHOA/app/TicTacWHOA`: open: /Users/vorousjames/Desktop/Development/TicTacWHOA/app/TicTacWHOA: Operation not permitted. Make sure watchman is running for this project. See https://facebook.github.io/watchman/docs/troubleshooting.html.
events.js:183
      throw er; // Unhandled 'error' event
  ^

Error: resolve_projpath: path `/Users/vorousjames/Desktop/Development/TicTacWHOA/app/TicTacWHOA`: open: /Users/vorousjames/Desktop/Development/TicTacWHOA/app/TicTacWHOA: Operation not permitted
    at BunserBuf.<anonymous> (/Users/vorousjames/Desktop/Development/TicTacWHOA/app/TicTacWHOA/node_modules/fb-watchman/index.js:95:23)
    at emitOne (events.js:116:13)
    at BunserBuf.emit (events.js:211:7)
    at BunserBuf.process (/Users/vorousjames/Desktop/Development/TicTacWHOA/app/TicTacWHOA/node_modules/bser/index.js:292:10)
    at /Users/vorousjames/Desktop/Development/TicTacWHOA/app/TicTacWHOA/node_modules/bser/index.js:247:12
    at _combinedTickCallback (internal/process/next_tick.js:131:7)
    at process._tickCallback (internal/process/next_tick.js:180:9)

This never happened before the Catalina update. I've had an empty watchman config file in the root of my project since the beginning. On first boot post-update, there was a popup in terminal saying something about permissions but i dont remember exactly. there's also a notice in my terminal in visual studio code saying "the default shell changed to zsh" run chsh -s /bin/zsh to change, so i did.

I've tried:

• watchman watch-del-all

• watchman server-shutdown

• adding full disk access to terminal from within system preferences->privacy tab

• npm uninstall watchman & npm uninstall -g watchman

I had the same issue after updating to Catalina. Wez Furlong's answer worked for me, but I had to provide full disk access to watchman in order to run watchman watch-project command without getting "Operation not permitted" error. As part of prior troubleshooting, I also had provided full disk access to Xcode and Terminal (not sure if this also contributed to the fix).

To change the permissions for Watchman regarding the Documents folder, it's under Security & Privacy -> files & folders in the system preferences

My issue was resolved by checking Watchman in the list under Document folder

You need to grant disk access to watchman. To do this You need to:

• Go to System preferences > Security & Privacy then scroll down
• Select Full Disk Access
• Unlock it and click + button to add new app/tool
• Select Macintosh HD in the folders list
• Press this combination shift Command . at the same time to see all the directories list
• Click opt > brew > bin (watchman is installed in this folder for MacOS Catalina) || usr > local > Cellar > Watchman > 21***** > bin (watchman is installed in this folder MacOS Monterey)
• Look for watchman in the list then select it

Here we go, this should fix the issue.

The error message indicates a permission problem on /Users/vorousjames/Desktop/Development/TicTacWHOA/app/TicTacWHOA.

However, it may be something funky with launchd, so I would suggest:

$ watchman shutdown-server
$ launchctl unload ~/Library/LaunchAgents/com.github.facebook.watchman.plist
$ rm ~/Library/LaunchAgents/com.github.facebook.watchman.plist
$ watchman watch-project /Users/vorousjames/Desktop/Development/TicTacWHOA/app/TicTacWHOA

and see if that works or shows more context.

Cross linking back to an issue in our GitHub tracker: https://github.com/facebook/watchman/issues/751

Just uncheck the repeated boxes in Mac:

System Preferences -> Security and privacy -> Privacy