Ruby On Rails常见错误解决办法

1、错误1，当执行rails server时，出现如下错误：

/usr/local/lib/ruby/gems/2.0.0/gems/execjs-2.0.2/lib/execjs/runtimes.rb:51:in `autodetect': Could not find a JavaScript runtime. See https://github.com/sstephenson/execjs for a list of available runtimes. (ExecJS::RuntimeUnavailable)

原因：没有js运行环境，解决方法：

vim Gemfile
    gem 'execjs'
    gem 'therubyracer'
bundle install
rails server

打开Gemfile添加gem 'execjs'，gem 'therubyracer'，然后安装bundle install，再执行rails server，就可以了。

2、错误2，Mac下当执行rails server时，出现如下错误：

dyld: lazy symbol binding failed: Symbol not found: _mysql_get_client_info    Referenced from: /Users/zxsoft/.rvm/gems/ruby-2.1.1@global/extensions/x86_64-darwin-13/2.1.0/mysql2-0.3.15/mysql2/mysql2.bundle
Expected in: flat namespace

dyld: Symbol not found: _mysql_get_client_info
Referenced from: /Users/zxsoft/.rvm/gems/ruby-2.1.1@global/extensions/x86_64-darwin-13/2.1.0/mysql2-0.3.15/mysql2/mysql2.bundle
Expected in: flat namespace

Trace/BPT trap: 5

已经使用gem install mysql2 安装过mysql2了。