https calling in NSOperation caused Segmentation fault

https_nsoperation.rb

framework 'Cocoa'
require 'net/https'

class SomeOperation < NSOperation
  def main
    http = Net::HTTP.new("mail.google.com", 443)
    http.use_ssl = true
    response = nil
    http.start do |h|
      req = Net::HTTP::Get.new("/mail/feed/atom")
      req.basic_auth('ashchan', 'pass')
      response = h.request(req)
    end
    puts response.code
  end
end

class AppDelegate
  def applicationDidFinishLaunching(notification)
    queue = NSOperationQueue.alloc.init
    2.times do
      queue.addOperation SomeOperation.new
    end
  end
end

app = NSApplication.sharedApplication
app.delegate = AppDelegate.new
app.run

# MacRuby 0.9
# macruby -w https_nsoperation.rb

# result:
# unknown: warning: Float 1.797693134862316E+3... out of range
# unknown: warning: Float 1.797693134862316E+3... out of range
# unknown: warning: instance variable @hostname not initialized
# unknown: warning: instance variable @hostname not initialized
# Segmentation fault