Ruby Rcov的Rspec2问题

在我的Rakefile中，我有一个任务定义如下：

namespace :test do
  desc "Run all specs."
  RSpec::Core::RakeTask.new(:spec) do |t|
    t.pattern = 'spec/**/*_spec.rb'
    t.verbose = false
  end

  RSpec::Core::RakeTask.new(:coverage) do |t|
    t.rcov = true
    t.rcov_opts =  %q[--exclude "spec"]
    t.verbose = true
  end
end

运行test:coverage时，我得到以下结果：

./spec/foo_spec.rb:3: undefined method `describe' for main:Object (NoMethodError)
    from /Library/Ruby/Gems/1.8/gems/rcov-0.9.9/bin/rcov:516:in `load'
    from /Library/Ruby/Gems/1.8/gems/rcov-0.9.9/bin/rcov:516
    from /usr/bin/rcov:19:in `load'
    from /usr/bin/rcov:19
rake aborted!
ruby -S rcov -Ispec:lib --exclude "spec" "./spec/foo_spec.rb" failed

以下是我的创业板名单：

diff-lcs (1.1.2)
rake (0.8.7)
rcov (0.9.9)
rspec (2.3.0)
rspec-core (2.3.1)
rspec-expectations (2.3.0)
rspec-mocks (2.3.0)

---

有什么想法吗？提前感谢。

解决方案，来自David Chelimsky:

干杯

require "rspec"