run specs multiple times with truncated output

run_spec_multiple.rb

#!/usr/bin/env ruby

ARGV[0].to_i.times do |i|
  puts "run #{i+1}"
  result = `rake SPEC=#{ARGV[1]}`
  puts result.match(/(Finished in \d+.\d+ seconds)/)[1]
  puts result.match(/(\d+ examples, \d+ failures?)/)[1]
  if result.match(/Failed examples:/)
    puts ''
    puts 'Failed examples:'
    puts result.split('Failed examples:').last
  end
end