This script removes and recreates all simulators in Xcode 7.

simulator_populator_xcode7

#!/usr/bin/env ruby

require 'JSON'

device_types = JSON.parse `xcrun simctl list -j devicetypes`
runtimes = JSON.parse `xcrun simctl list -j runtimes`
devices = JSON.parse `xcrun simctl list -j devices`

devices['devices'].each do |runtime, runtime_devices|
  runtime_devices.each do |device|
    puts "Removing device #{device['name']} (#{device['udid']})"
    `xcrun simctl delete #{device['udid']}`
  end
end

device_types['devicetypes'].each do |device_type|
  runtimes['runtimes'].select{|runtime| runtime['availability'] == '(available)'}.each do |runtime|
    puts "Creating #{device_type['name']} with #{runtime['name']}"
    command = "xcrun simctl create '#{device_type['name']} #{runtime['name']}' #{device_type['identifier']} #{runtime['identifier']}"
    command_output = `#{command}`
    sleep 0.5
  end
end

Warning: This is completely untested. It will REMOVE all your simulators along with all settings and installed Apps. It worked for me to create the initial set of simulators.

Follow these guidelines to use this script : http://stackoverflow.com/a/35600096/1996802

If you're using a more recent version of Ruby, you may need to change require 'JSON' to require 'json'

Great, looks good! Just one strange thing - I get these errors:

Creating iPad Air 2 with iOS 9.2
Creating iPad Air 2 with tvOS 9.1
An error was encountered processing the command (domain=com.apple.CoreSimulator.SimError, code=157):
Incompatible device
Creating iPad Air 2 with watchOS 2.1
An error was encountered processing the command (domain=com.apple.CoreSimulator.SimError, code=157):
Incompatible device

for almost every device… I mean it doesn't seem to make sense to e.g. create "iPad Air 2 with tvOS 9.1", so I guess this is OK?
Maybe you can do some check in the inner loop when creating, to prevent these errors.

Thanks for the script, it helps a lot. But it seems that it creates all simulators for every version and device in xcode, even they are not downloaded yet.

If you are a CocoaPod writer, You might want to change line 19 from

command = "xcrun simctl create '#{device_type['name']} #{runtime['name']}' #{device_type['identifier']} #{runtime['identifier']}"

to

command = "xcrun simctl create '#{device_type['name']}' #{device_type['identifier']} #{runtime['identifier']}"

to omit generating simulator names like iPhone 4s iOS 9.3 and generate iPhone 4s instead, otherwise it causes: CocoaPods/CocoaPods#5320 (comment)