How to fix “Unable to boot device” error message in Xcode 9?

Question

I am consistently getting Unable to determine simulator device to boot error after deleting the ~/Library/Developer/CoreSimulator/Devices directory.

Tried restarting xcode, clean build but nothing works!

Answer 1

I have found the easiest and straightforward solution. Happy to share with the community!

Steps -

• gem install snapshot - Skip this step if you already have snapshot installed.
• fastlane snapshot reset_simulators

No need to try following steps -

• remove and add simulator using Manage devices

• restart mac

• try to open simulator from Xcode -> Open Developer Tool

• sudo commands etc.

These solutions sometimes work but often they don't. So next time just try fastlane snapshot reset_simulators