Gemfile对冲突的单一依赖性导致冲突

Question

我是Ruby和Rails的新手，我正在尝试遵循Spree的指示，但是在执行bundle install时，我遇到了依赖项解决方案的问题。我已经搜索了许多类似的问题，但是在所有这些问题中，有几个在Gemfile中的"根"宝石。就我而言，我已经单根spree (~> 3.1.0.rc1)甚至相同的依赖树。看起来单GEM Rails 4.2.6取决于actionpack 5.0.2和4.2.6的两个版本。怎么可能？

Bundler could not find compatible versions for gem "actionpack":
In Gemfile:
  spree (~> 3.1.0.rc1) was resolved to 3.1.0.rc1, which depends on
    spree_core (= 3.1.0.rc1) was resolved to 3.1.0.rc1, which depends on
      rails (~> 4.2.6) was resolved to 4.2.6, which depends on
        actionpack (= 5.0.2)
  spree (~> 3.1.0.rc1) was resolved to 3.1.0.rc1, which depends on
    spree_core (= 3.1.0.rc1) was resolved to 3.1.0.rc1, which depends on
      rails (~> 4.2.6) was resolved to 4.2.6, which depends on
        actionpack (= 5.0.2)
  spree (~> 3.1.0.rc1) was resolved to 3.1.0.rc1, which depends on
    spree_core (= 3.1.0.rc1) was resolved to 3.1.0.rc1, which depends on
      rails (~> 4.2.6) was resolved to 4.2.6, which depends on
        actionpack (= 4.2.6)

P.S。我能够通过在Gemfile中指定gem 'rails', '>= 4.2.7'来解决问题。这仍然满足条件〜> 4.2.6，不包含所述问题。但是我仍然很好奇如何描述状态。

谢谢！

Answer 1

这是因为您使用的是错误的轨道和狂欢版本不匹配，因此它们与彼此不兼容。

铁轨5：

gem 'spree', '~> 3.2.0'

铁轨4：

gem 'spree', '~> 3.1.0'