'Failed to start Watchman watch mode

I am developing a React Native app. My code is error free, but it is facing build problems. I get an error in the Metro Bundler when I execute the command react-native run-android. The error says:

UnhandledPromiseRejectionWarning: Failed to start watch mode.

I also tried adding Watchman to node_modules using the command $yarn add watchman. I get a prompt that it is deprecated.

How should I solve the error?

My package.json contains the following:

"dependencies": {
    "expo": "^25.0.0",
    "native-base": "^2.3.7",
    "react": "16.2.0",
    "react-native": "0.52.0",
    "react-native-vector-icons": "^4.5.0",
    "react-navigation": "^1.0.0-beta.27",
    "watchman": "^1.0.0"
}

"devDependencies": {
    "babel-jest": "22.1.0",
    "babel-preset-react-native": "4.0.0",
    "jest": "22.1.3",
    "react-test-renderer": "16.2.0"
  }

react-native watchman

Solution 1:^[1]

You have to install watchman using brew:

brew install watchman

Solution 2:^[2]

in windows npm install watchman

Solution 3:^[3]

I have also faced the same issue.Then I have

Deleted the node modules and installed them again by using npm install.
Then clean gradle by '.\gradlew'
Then run the app by 'npx react-native run-android'.

The above steps helped me to resolve the error.

Solution 4:^[4]

I tried the following:

Restarting my system
Deleting npm/yarn cache.

Most of the times the above methods worked but not always. So, here's one-time permanent solution (for Windows)

Download the Watchman v2021.01.11
Unzip, Rename the folder "Watchman" and paste the C:/Program Files.
Open the folder and copy the location of bin folder (would be C:/Program Files/Watchman/bin)
Go to Environment variables, search of PATH variable and append the copied location of bin

Solution 5:^[5]

Failed to start Watchman watch mode (Windows)

I tried a lot to fixed the issue and at last, I restart my windows now it's working.

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution	Source
Solution 1	Michal
Solution 2	art_cs
Solution 3	Nk54
Solution 4	Rahul
Solution 5	lak singh

'Failed to start Watchman watch mode

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