没有兼容版本、与版本要求相矛盾的“包更新”报告宝石

Question

“包更新”给了我一些非常奇怪的错误。arel，activemodel和齿条在下面列出，因为它们没有兼容的版本。每一个都列出了两次，但版本要求是相互矛盾的：

$ bundle update
Updating https://github.com/bborn/communityengine.git
Updating https://github.com/bborn/authlogic.git
Updating https://github.com/paneq/calendar_date_select.git
Fetching source index for http://rubygems.org/
Bundler could not find compatible versions for gem "arel":
  In Gemfile:
    community_engine (= 2.0.0.beta) depends on
      arel (~> 2.1.1)

    community_engine (= 2.0.0.beta) depends on
      arel (2.2.1)

Bundler could not find compatible versions for gem "activemodel":
  In Gemfile:
    community_engine (= 2.0.0.beta) depends on
      activemodel (= 3.1.0.beta1)

    community_engine (= 2.0.0.beta) depends on
      activemodel (3.1.0.rc2)

Bundler could not find compatible versions for gem "rack":
  In Gemfile:
    community_engine (= 2.0.0.beta) depends on
      rack (= 1.3.2)

    community_engine (= 2.0.0.beta) depends on
      rack (1.3.3)

gem列表显示安装了合适的版本：

rack (1.3.3, 1.3.2)
arel (2.2.1, 2.1.1)
activemodel (3.1.0, 3.1.0.rc2, 3.1.0.beta1)

变得更奇怪了。将Gemfile中的另外3行从末尾移到中间(在“source”和“gem rails”行之后)会更改包报告的错误：

Bundler could not find compatible versions for gem "actionpack":
  In Gemfile:
    rails (= 3.1.0) depends on
      actionpack (= 3.1.0)

    community_engine (= 2.0.0.beta) depends on
      actionpack (3.1.0.rc2)

Bundler could not find compatible versions for gem "rack":
  In Gemfile:
    community_engine (= 2.0.0.beta) depends on
      rack (= 1.3.2)

    community_engine (= 2.0.0.beta) depends on
      rack (1.3.3)

community_engine gem无疑是值得怀疑的，我也在他们的论坛上寻找答案。但是，这种来自邦德勒的奇怪错误需要更广泛的观众。

有什么建议吗，伙计们？太棒了！

Answer 1

FWIW在community的README.markdown (https://github.com/bborn/communityengine/blob/master/README.markdown)上写道：

需求：

• RAILS版本2.3.4 (尚不支持更高版本)

但是看起来你在尝试使用Rails 3.1吗？