Sqlite3-ruby缺少。但不是真的

Question

所以背景细节：我在Ubuntu 12.04中运行Ruby 2.2.0和Rails 4.1.0。

当我输入rails -v时，收到错误消息：

Could not find gem 'sqlite3-ruby (= 1.3.1) ruby' in the gems available on this machine.
Try running `bundle install`.

当我输入bundle install时：

我明白了：

Fetching gem metadata from http://rubygems.org/...........
Fetching version metadata from http://rubygems.org/..
Resolving dependencies...
Bundler could not find compatible versions for gem "bundler":
  In Gemfile:
    rails (= 3.0.1) ruby depends on
      bundler (~> 1.0.0) ruby

  Current Bundler version:
    bundler (1.8.4)

This Gemfile requires a different version of Bundler.
Perhaps you need to update Bundler by running `gem install bundler`?

最糟糕的是，它仍然显示Rails（3.0.1），这不是我计算机上当前版本的rails。

我尝试输入：

来安装sqllite3-ruby

sudo apt-get install libsqlite3-dev

但我明白了：

Reading package lists... Done
Building dependency tree       
Reading state information... Done
libsqlite3-dev is already the newest version.
The following packages were automatically installed and are no longer required:
  ruby-builder ruby-blankslate ruby-text-format ruby-activesupport-2.3 rubygems ruby-i18n rake libjs-prototype libmemcache-client-ruby1.8
  ruby-actionmailer-2.3 libmemcache-client-ruby ruby-activerecord-2.3 ruby-rchardet ruby-rack ruby-tmail libjs-scriptaculous libtzinfo-ruby1.8
  ruby-rails-2.3 ruby-activeresource-2.3 libtzinfo-ruby ruby-actionpack-2.3
Use 'apt-get autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 455 not upgraded.

更新

Answer 1

检查Gemfile中的rails版本。您的应用程序似乎是使用rails 3.0.1构建的。所以bundle install想要安装Gemfile中请求的所有gem版本。正如您终端中的消息所说，rails 3.0.1依赖于bundler 1.0.0，但您目前已安装了bundler 1.8.4。

哟有两种可能性：将您现有的应用程序升级到您的intsalled rails版本（4.2.0）或将所有已安装的依赖于rails的gem降级为rails 3.0.1。