rails server 命令找不到库

Question

我已经安装了 rails、mysql2 gem 和 mysql，并使用rails new simple_cms -d mysql 创建了一个名为 simple_cms 的项目。现在，当我执行rails server 启动WEBricks 时，我得到了这样的快乐：

/Library/Ruby/Gems/1.8/gems/mysql2-0.3.11/lib/mysql2/mysql2.bundle: dlopen(/Library/Ruby/Gems/1.8/gems/mysql2-0.3.11/lib/mysql2/mysql2.bundle, 9): Library not loaded: /usr/local/mysql/lib/libmysqlclient.16.dylib (LoadError)
  Referenced from: /Library/Ruby/Gems/1.8/gems/mysql2-0.3.11/lib/mysql2/mysql2.bundle
  Reason: image not found - /Library/Ruby/Gems/1.8/gems/mysql2-0.3.11/lib/mysql2/mysql2.bundle
    from /Library/Ruby/Gems/1.8/gems/mysql2-0.3.11/lib/mysql2.rb:9
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.21/lib/bundler/runtime.rb:68:in `require'
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.21/lib/bundler/runtime.rb:68:in `require'
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.21/lib/bundler/runtime.rb:66:in `each'
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.21/lib/bundler/runtime.rb:66:in `require'
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.21/lib/bundler/runtime.rb:55:in `each'
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.21/lib/bundler/runtime.rb:55:in `require'
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.21/lib/bundler.rb:122:in `require'
    from /Users/tyre77/Dropbox/Broetry In Motion/RailsTestApp/simple_cms/config/application.rb:7
    from /Library/Ruby/Gems/1.8/gems/railties-3.2.1/lib/rails/commands.rb:53:in `require'
    from /Library/Ruby/Gems/1.8/gems/railties-3.2.1/lib/rails/commands.rb:53
    from /Library/Ruby/Gems/1.8/gems/railties-3.2.1/lib/rails/commands.rb:50:in `tap'
    from /Library/Ruby/Gems/1.8/gems/railties-3.2.1/lib/rails/commands.rb:50
    from script/rails:6:in `require'
    from script/rails:6

我已将 .bash_profile 更改为如下所示：（不确定是否相关）

PS1="\u \w$ "
alias ll="ls -lahG"

export PATH="/usr/local/bin:/usr/local/sbin:/usr/local/mysql/bin:/$PATH"


# include .bashrc if it exists
if [ -f $HOME/.bashrc ]; then
    . $HOME/.bashrc
fi

# startup virtualenv-burrito
if [ -f $HOME/.venvburrito/startup.sh ]; then
    . $HOME/.venvburrito/startup.sh
fi

见： Unable to start rails server 但我的 mysql 版本不同，即使将 0.2.6 更改为 0.3.11 也无法解决

Answer 1

问题是 Ruby 找不到构建 MySQL gem 所需的库，有很多方法可以解决这个问题，但由于您似乎刚刚开始使用 Ruby，我认为准备好您的环境是值得的这样你就不会再看到这种东西了，步骤如下：

首先我建议你安装Homebrew，安装 Homebrew，安装 MySQL：

brew install mysql

这将在您的机器中安装 MySQL，包括在您需要时构建 MySQL gem 所需的库。

然后你应该安装RVM 来安装你的rubies（在安装RVM之前你需要运行brew install git）。安装 RVM 后，您就可以开始安装任何您想要的 rubies。

然后你问，为什么不能使用内置的 Ruby？ Rails 将在 4.0 上放弃对 Ruby 1.8.* 分支的支持，社区通常使用 RVM（或 rbenv）来安装和管理安装到您机器上的 rubies。