react-native

Launching two instances of a react-native project in two simulators

You’ll see this error when you try to run the second instance

error Failed to launch the app on simulator, An error was encountered processing the command (domain=com.apple.CoreSimulator.SimError, code=405):
Unable to lookup in current state: Shutdown

This is because react-native runner won’t start the second emulator instance automatically. You need to start it by opening xcode -> window -> devices & simulators -> simulators -> start the desired simulator.

Then you can run npx react-native run-ios --simulator="iPhone XXX" again

Or you can just run the program in XCode and select the second simulator.

When cannot connect to EC2 instance with external IP

• Check the subnet’s routing table
• There should be an igw-something route. If not, won’t be able to connect to the instance from the internet
• Select a different subnet if such a function is desired
• Don’t need to allocate an Elastic IP address

gvm install go1.14

• Will install go 1.14.0 (not the latest version of go)
• Must specify specific version of go to install latest (which is different from nvm)