rake多次重复相同的测试

Question

我在我的Rails应用程序中添加了一个新的（普通旧的）ruby类。我有一个最小的单元测试：

require 'minitest_helper'
class ReportOptionTest < MiniTest::Unit::TestCase
  def setup
    @report_option = Cmdx::ReportGenerator::ReportOption.new( "testing123" )
  end

  def test_depends_on
    assert @report_option.depends_on.empty?
  end
end

如果我通过rake运行这个测试，它就像我预期的那样运行，但它运行六次，我没有：

$ time rake test TEST=test/unit/report_generator/report_option_test.rb 
Rack::File headers parameter replaces cache_control after Rack 1.5.
Run options: --seed 64427

# Running tests:
.

Finished tests in 0.003272s, 305.6309 tests/s, 305.6309 assertions/s.

1 tests, 1 assertions, 0 failures, 0 errors, 0 skips
Rack::File headers parameter replaces cache_control after Rack 1.5.
Run options: --seed 17980

# Running tests:
.

Finished tests in 0.003284s, 304.4809 tests/s, 304.4809 assertions/s.

1 tests, 1 assertions, 0 failures, 0 errors, 0 skips
Rack::File headers parameter replaces cache_control after Rack 1.5.
Run options: --seed 45845

# Running tests:
.

Finished tests in 0.003267s, 306.0590 tests/s, 306.0590 assertions/s.

1 tests, 1 assertions, 0 failures, 0 errors, 0 skips
Rack::File headers parameter replaces cache_control after Rack 1.5.
Run options: --seed 49526

# Running tests:
.

Finished tests in 0.003258s, 306.9620 tests/s, 306.9620 assertions/s.

1 tests, 1 assertions, 0 failures, 0 errors, 0 skips
Rack::File headers parameter replaces cache_control after Rack 1.5.
Run options: --seed 53716

# Running tests:
.

Finished tests in 0.003246s, 308.1155 tests/s, 308.1155 assertions/s.

1 tests, 1 assertions, 0 failures, 0 errors, 0 skips
Rack::File headers parameter replaces cache_control after Rack 1.5.
Run options: --seed 44898

# Running tests:
.

Finished tests in 0.003272s, 305.6556 tests/s, 305.6556 assertions/s.

1 tests, 1 assertions, 0 failures, 0 errors, 0 skips

real   0m34.999s
user   0m32.034s
sys    0m1.440s

我注意到this page提到了类似的问题。我不明白发生了什么，以及是否有一些配置设置我需要更改为只运行一次测试，坦率地说，让测试运行得更快。

版本：

$ ruby -v
ruby 1.9.3p362 (2012-12-25 revision 38607) [x86_64-linux]
$ rake -V
rake, version 10.0.3
$ rails -v
Rails 3.2.12