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

Question

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

Answer 1

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).