class ParallelTests::RSpec::Runner

def self.determine_executable
  cmd = if File.file?("script/spec")
    "script/spec"
  elsif ParallelTests.bundler_enabled?
    cmd = (run("bundle show rspec-core") =~ %r{Could not find gem.*} ? "spec" : "rspec")
    "bundle exec #{cmd}"
  else
    %w[spec rspec].detect{|cmd| system "#{cmd} --version > /dev/null 2>&1" }
  end
  cmd or raise("Can't find executables rspec or spec")
end