Metro Bundler immediately closes after react-native run-android

[thecodrr]

Environment

System:
 OS: Windows 10
 CPU: (8) x64 Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz
 Memory: 8.99 GB / 15.89 GB
 Binaries:
 Node: 10.16.0 - C:\Program Files\nodejs\node.EXE
 Yarn: 1.16.0 - C:\Program Files (x86)\Yarn\bin\yarn.CMD
 npm: 6.9.0 - C:\Program Files\nodejs\npm.CMD
 SDKs:
 Android SDK:
 Android NDK: 18.1.5063045
 IDEs:
 Android Studio: Version 3.3.0.0 AI-182.5107.16.33.5264788

react-native-cli: 2.0.1
react-native: 0.60.0

Description

Doing yarn react-native run-android opens the metro bundler but it immediately closes. Don't know if its a bug with the cli or the metro itself. This only happens on Windows, I think.

Things I have tried:

1. Restarting my system
2. Clearing cache etc.

Reproducible Demo

1. Create a new project using react-native init
2. Run yarn react-native run-android

[thymikee]

We'll need help debugging what's causing this. What does it mean that "it closes"? Can you share more details?

[thecodrr]

@thymikee well I can't see the error on it as it only blinks. How can I debug it?

Edit: after looking really closely, the Metro Bundler window is completely empty when it closes, so no error there.

[thymikee]

Can you post a video? :D Set up some console.logs in commands/server/runServer.js

[thecodrr]

@thymikee runServer gives nothing so it's not even getting there.

[thymikee]

Btw, does running yarn react-native start works without issues? If so, check files related to this diff: #310

[thecodrr]

Running launchPackager.bat directly gives this error:
error: unknown option --projectRoot'`

[thecodrr]

Doing yarn react-native start gives me the console.logs I had set so I am guessing, runServer is getting called in that case.

[thecodrr]

Running node .\node_modules\react-native\cli.js --projectRoot also gives this error:
error: unknown option `--projectRoot'

[thymikee]

Yea, because we removed this option. It's not necessary now. Can you remove it from https://github.com/facebook/react-native/blob/master/scripts/launchPackager.bat and see if that works?

[thecodrr]

@thymikee yup. Working without a hitch.

[thymikee]

Yea, can you send a PR to RN? The patch release make take a while (cc @kelset). I think we should own these files, but that may be a bit bigger change.