Don’t know how to build task ‘default’

这是我的Rakefile

require 'rake/testtask'

Rake::TestTask.new do |t|
  t.test_files = FileList['test/*_test.rb']
end

而test / unit_test.rb中的虚拟文件

require 'minitest/autorun'

class TestPackage < MiniTest::Unit::TestCase

  def test
    assert_equal 10,Array.new(10).size
  end
end

如果我将Rakefile更改为包含任务：default => ‘minitest’的错误信息改变为不知道如何构建任务’minitest’

rake –trace似乎只是把我引回到处理任务调用的Rake gem的部分.没有线索我可以看到：

~/.rbenv/versions/1.9.3-p286/lib/ruby/1.9.1/rake/task_manager.rb:49:in `[]'
~/.rbenv/versions/1.9.3-p286/lib/ruby/1.9.1/rake/application.rb:115:in `invoke_task'
~/.rbenv/versions/1.9.3-p286/lib/ruby/1.9.1/rake/application.rb:94:in `block (2 levels) in top_level'
~/.rbenv/versions/1.9.3-p286/lib/ruby/1.9.1/rake/application.rb:94:in `each'
~/.rbenv/versions/1.9.3-p286/lib/ruby/1.9.1/rake/application.rb:94:in `block in top_level'
~/.rbenv/versions/1.9.3-p286/lib/ruby/1.9.1/rake/application.rb:133:in `standard_exception_handling'
~/.rbenv/versions/1.9.3-p286/lib/ruby/1.9.1/rake/application.rb:88:in `top_level'
~/.rbenv/versions/1.9.3-p286/lib/ruby/1.9.1/rake/application.rb:66:in `block in run'
~/.rbenv/versions/1.9.3-p286/lib/ruby/1.9.1/rake/application.rb:133:in `standard_exception_handling'
~/.rbenv/versions/1.9.3-p286/lib/ruby/1.9.1/rake/application.rb:63:in `run'
~/.rbenv/versions/1.9.3-p286/bin/rake:32:in `<main>'