Xcode 12 deployment target warnings when using CocoaPods

A short working solution is here! Just copy and paste the code snippet at the end of your Podfile and run the pod install command.

    post_install do |installer|
     installer.pods_project.targets.each do |target|
         target.build_configurations.each do |config|
            if config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'].to_f < 12.0
              config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = '12.0'
            end
         end
     end
  end

In this case, 12.0 is the minimum supporting iOS version for AppStore submission. You can change it based on your project requirements.