为什么bundler找不到兼容的版本？

Question

我正在尝试升级一些gem，bundler在执行bundle update时给了我以下建议

Bundler could not find compatible versions for gem "actionmailer":
  In Gemfile:
    devise_invitable was resolved to 2.0.1, which depends on
      actionmailer (>= 5.0)

    rails (= 5.1.7) was resolved to 5.1.7, which depends on
      actionmailer (= 5.1.7)

我不明白为什么它不使用5.1.7？

还有另一个例子：

Bundler could not find compatible versions for gem "redis":
  In Gemfile:
    redis (~> 3.3.1)

    redis-objects (~> 1.2.1) was resolved to 1.2.1, which depends on
      redis (>= 3.0.2)

    sidekiq-limit_fetch was resolved to 3.4.0, which depends on
      sidekiq (>= 4) was resolved to 5.2.8, which depends on
        redis (>= 3.3.5, < 5)

    sidekiq_newrelic_monitor was resolved to 0.1.2, which depends on
      redis

    split (~> 3.2.0) was resolved to 3.2.0, which depends on
      redis (>= 2.1)

为什么不直接使用3.3.x呢？

Bundler版本1.17.3

来自评论的更新：

cat Gemfile.lock | grep 'redis'
      redis
      redis
    redis (3.3.5)
    redis-objects (1.2.1)
      redis (>= 3.0.2)
      redis (>= 3.3.5, < 5)
      redis (>= 2.1)
  redis (~> 3.3.1)
  redis-objects (~> 1.2.1)

Answer 1

因此，事实证明，bundler 1.x在正确报告依赖关系问题时存在问题，因此我升级到2.x以更好地发现它。我通过从我的gemfiles中注释掉除了rails之外的所有东西来做到这一点。然后一次运行一个bundle update，同时在越来越多的gem中进行评论。当依赖性问题浮出水面时，它解决了这些问题。

Answer 2

你能把actionmailer的版本指定为你认为可以解决它的版本吗，比如：actionmailer, 5.1.7

Answer 3

如果您在运行bundle update时遇到问题，您可以删除Gemfile.lock文件，然后再次运行bundle update重新生成Gemfile.lock，这可能会解决问题。