Add "npm run build silently fails" to Troubleshooting (facebook#1168)

* Add "npm run build silently fails" to Troubleshooting

* Update README.md

Author: gaearon

packages/react-scripts/template/README.md

@@ -55,6 +55,8 @@ You can find the most recent version of this guide [here](https://github.com/fac
   - [S3 and CloudFront](#s3-and-cloudfront)
   - [Surge](#surge)
 - [Troubleshooting](#troubleshooting)
+  - [`npm test` hangs on macOS Sierra](#npm-test-hangs-on-macos-sierra)
+  - [`npm run build` silently fails](#npm-run-build-silently-fails)
 - [Something Missing?](#something-missing)
 
 ## Updating to New Releases
@@ -1118,6 +1120,10 @@ If this still doesn't help, try running `launchctl unload -F ~/Library/LaunchAge
 
 There are also reports that *uninstalling* Watchman fixes the issue. So if nothing else helps, remove it from your system and try again.
 
+### `npm run build` silently fails
+
+It is reported that `npm run build` can fail on machines with no swap space, which is common in cloud environments. If [the symptoms are matching](https://github.com/facebookincubator/create-react-app/issues/1133#issuecomment-264612171), consider adding some swap space to the machine you’re building on, or build the project locally.
+
 ## Something Missing?
 
 If you have ideas for more “How To” recipes that should be on this page, [let us know](https://github.com/facebookincubator/create-react-app/issues) or [contribute some!](https://github.com/facebookincubator/create-react-app/edit/master/packages/react-scripts/template/README.md)