React native - connection has no connection handler error meaning?

Question

I created a new react project and when I run it on iOS from xcode, the console gives me this:

2017-05-19 23:25:34.119 [info][tid:main][RCTBatchedBridge.m:77] Initializing <RCTBatchedBridge: 0x6100001a6c80> (parent: <RCTBridge: 0x6100000c46e0>, executor: RCTJSCExecutor) 2017-05-19 23:25:51.287 [info][tid:main][RCTRootView.m:295] Running application test ({     initialProps =     {     };     rootTag = 1; }) 2017-05-19 23:25:51.289 [info][tid:com.facebook.react.JavaScript] Running application "test" with appParams: {"rootTag":1,"initialProps":{}}. __DEV__ === true, development-level warning are ON, performance optimizations are OFF 2017-05-19 23:25:51.299771-0400 test[21948:1121429] [] nw_connection_get_connected_socket_block_invoke 3 Connection has no connected handler 2017-05-19 23:25:53.335282-0400 test[21948:1121426] [] nw_connection_get_connected_socket_block_invoke 4 Connection has no connected handler 2017-05-19 23:25:55.349190-0400 test[21948:1120112] [] nw_connection_get_connected_socket_block_invoke 5 Connection has no connected handler 

What do 2017-05-19 23:25:51.299771-0400 test[21948:1121429] [] nw_connection_get_connected_socket_block_invoke 3 Connection has no connected handler these lines mean and how to I resolve the issue?

I first noticed this when I tried to use fetch in my application and found it did not work. I found these messages in the console and later discovered these messages are happening with all my applications so I assume that means it is a config issue on my part?

I created a new test program to test what was causing this and found it happens on a brand new project. Below is my code is that generated the log output above:

/**  * Sample React Native App  * https://github.com/facebook/react-native  * @flow  */  import React, { Component } from 'react'; import {   AppRegistry,   StyleSheet,   Text,   View } from 'react-native';  export default class test extends Component {   render() {     return (       <View style={styles.container}>         <Text style={styles.welcome}>           Welcome to React Native!         </Text>         <Text style={styles.instructions}>           To get started, edit index.ios.js         </Text>         <Text style={styles.instructions}>           Press Cmd+R to reload,{'\n'}           Cmd+D or shake for dev menu         </Text>       </View>     );   } }  const styles = StyleSheet.create({   container: {     flex: 1,     justifyContent: 'center',     alignItems: 'center',     backgroundColor: '#F5FCFF',   },   welcome: {     fontSize: 20,     textAlign: 'center',     margin: 10,   },   instructions: {     textAlign: 'center',     color: '#333333',     marginBottom: 5,   }, });  AppRegistry.registerComponent('test', () => test); 

Answer 1

Try Below process

Xcode menu -> Product -> Edit Scheme...

Environment Variables -> Add -> Name: "OS_ACTIVITY_MODE", Value:"disable"

Run your app again

Answer 2

I figured out the solution:

To turn off Verbose for OS Activity Mode

1. From the xcode menu, Project -> Scheme -> Edit Scheme.
2. Then select Run on the left and then select Arguments tab on the right.
3. In Environment Variables add the name OS_ACTIVITY_MODE and value as disable.

Or see picture below.

Note: credit for image goes to Ramkrishna Sharma