Debugging common errors

Most errors with building can be fixed with all or some subset of the following:

• npm install and restarting the packager
  • Should be done after pulling in new commits that have changed package.json
• git clean -dfx -e config and then npm install
  • git clean removes files. Run git clean -dfx -e config --dry-run to see what files will be changed without actually performing any of the changes.
  • Sometimes npm install on its own is insufficient to correct dependency issues, or sometimes there are residual generated files that are in .gitignore that need to be cleaned up.
  • Can be done to fix non-application-level errors that may occur in the app or in xcode.
• Installing watchman
  • There will typically be an error inside of the app that will say something about not being able to run watchman.
• If watchman was already installed, then watchman watch-del-all
  • Can be done to fix packager dependency resolution errors.
• (warning: type this in correctly, and make sure it's not deleting anything else important) rm -rf $TMPDIR/react-native-packager-*
  • Can also be done to fix packager dependency resolution errors.
• In Xcode, running Product -> Clean (shift-cmd-k).
  • Can fix errors with internal errors resolving internal React functions that arise when building in Xcode.