'React native run android' stop immediatelly after start the app in emulator

Question

I'm trying to test my Android application but when I start it with react-native run-android command after it is start on the device inmediatelly stop without error.

I got this:

This build could be faster, please consider using the Gradle Daemon: https://docs.gradle.org/2.14.1/userguide/gradle_daemon.html
Running adb -s emulator-5556 reverse tcp:8081 tcp:8081
Starting the app on emulator-5556 (adb -s emulator-5556 shell am start -n com.app/.MainActivity)...
Starting: Intent { cmp=com.app/.MainActivity }

After I get back the prompt but not always, if I keep on try it is sometimes running properly, but I have to run this 10-15 times. The SDK version is 25 and I followed the React Native Getting Started installation guide.

• OS: Fedora 24
• React-native: 0.42.0

UPDATE:

I tryed out with react-native start and it was said for me Loading dependency graph... ERROR Packager can't listen on port 8081 but I don't understand why the previous command didn't said it for me. In this case I can change the port with the --port 9000, but I didn't found any other flag for the in the react-native run-android command.

UPDATE 2:

It seems the problem occured because the remote debugger switched on on the device and it's connected to the remote debugger on the :8081 port and the adb wanted to create a new server for the mobile app through the :8081 for a while the old remote debug is still occupy the :8081 port, so it wasn't allow to create a new one. I switched off the remote debugger and it is running without problem. I'm not sure about that it's possible it was the problem.

Answer 1

i was having the same problem in ubuntu what worked for me is that i closed terminal removed my device from usb restarted. first of all would suggest you add these lines inside your packages.json replace scripts with this

"scripts": {
"prepare-repository": "npm i -g react-native-cli yarn;yarn install; react- native link",
"emulator": "emulator -avd Nexus5V6L23_x86_64 -scale 1.0",
"install": "react-native run-android",
"start": "react-native start --reset-cache",
"android": "npm run install && npm run start",
"clean": "watchman watch-del-all && npm cache clean && cd android && ./gradlew clean && cd ..",
"test": "jest"
}

After that save it and then go to the folder where u created project. lets say mine home/workspace/demo. Inside that run script

 npm run clean //this will clear all cache

after that

npm run android 

It will run app in device as well as start-reset cache.Let me know if it helps.

Sometimes adding

adb reverse tcp:8081

before running npm run android does the trick I will recommend you to enable Gradle daemon it really makes your build faster. To enable it goto android->gradle.properties and inside that file write

org.gradle.daemon=true

Answer 2

I had the same issue and problem is described here port already in use. So just kill the process occupying the port.

sudo lsof -i :8081

kill -9 <PID>