In iOS ,when I down the code ,and then user command : react-native-git-upgrade ,and then has error:Cannot find entry file index.js in any of the roots

[bosenboy]

error: bundling failed: NotFoundError: Cannot find entry file index.js in any of the roots: ["/Users/bosen/Desktop/GitHubPopular"]
at DependencyGraph.getAbsolutePath (/Users/bosen/Desktop/GitHubPopular/node_modules/metro/src/node-haste/DependencyGraph.js:317:11)
at /Users/bosen/Desktop/GitHubPopular/node_modules/metro/src/DeltaBundler/DeltaCalculator.js:280:416
at Generator.next ()
at step (/Users/bosen/Desktop/GitHubPopular/node_modules/metro/src/DeltaBundler/DeltaCalculator.js:11:445)
at /Users/bosen/Desktop/GitHubPopular/node_modules/metro/src/DeltaBundler/DeltaCalculator.js:11:605
at process._tickCallback (internal/process/next_tick.js:68:7)
BUNDLE [ios, dev] ./index.js 0.0% (0/1), failed.