spec_helper.rb

    # stdout, stderr pipes
    rout, wout = IO.pipe
    rerr, werr = IO.pipe

    Process.spawn('rake run_fake_service', :out => wout, :err => werr)

    # close write ends so we could read them
    wout.close
    werr.close

    stdout = rout.readlines.join("\n")
    stderr = rerr.readlines.join("\n")