由于“mysql2”gem，我无法运行“bundle update”
我在Gemfile中有这个：
gem 'mysql2' 但是当我运行bundle update时 ，我收到以下错误消息：
An error occurred while installing mysql2 (0.3.16), and Bundler cannot continue. Make sure that `gem install mysql2 -v '0.3.16'` succeeds before bundling.
我试着把它移到生产部分，像这样：
group :production do gem 'mysql2' end
但是在运行bundle更新后 ，结果是一样的。 此部分仅在生产模式下处理，还是不处理？
如何摆脱localhost上的此错误消息？
编辑：整个错误消息：
Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension. /Users/radek/.rvm/rubies/ruby-1.9.3-p385/bin/ruby extconf.rb checking for ruby/thread.h... *** extconf.rb failed *** Could not create Makefile due to some reason, probably lack of necessary libraries and/or headers. Check the mkmf.log file for more details. You may need configuration options. Provided configuration options: --with-opt-dir --with-opt-include --without-opt-include=${opt-dir}/include --with-opt-lib --without-opt-lib=${opt-dir}/lib --with-make-prog --without-make-prog --srcdir=. --curdir --ruby=/Users/radek/.rvm/rubies/ruby-1.9.3-p385/bin/ruby /Users/radek/.rvm/rubies/ruby-1.9.3-p385/lib/ruby/1.9.1/mkmf.rb:381:in `try_do': The compiler failed to generate an executable file. (RuntimeError) You have to install development tools first. from /Users/radek/.rvm/rubies/ruby-1.9.3-p385/lib/ruby/1.9.1/mkmf.rb:506:in `try_cpp' from /Users/radek/.rvm/rubies/ruby-1.9.3-p385/lib/ruby/1.9.1/mkmf.rb:931:in `block in have_header' from /Users/radek/.rvm/rubies/ruby-1.9.3-p385/lib/ruby/1.9.1/mkmf.rb:790:in `block in checking_for' from /Users/radek/.rvm/rubies/ruby-1.9.3-p385/lib/ruby/1.9.1/mkmf.rb:284:in `block (2 levels) in postpone' from /Users/radek/.rvm/rubies/ruby-1.9.3-p385/lib/ruby/1.9.1/mkmf.rb:254:in `open' from /Users/radek/.rvm/rubies/ruby-1.9.3-p385/lib/ruby/1.9.1/mkmf.rb:284:in `block in postpone' from /Users/radek/.rvm/rubies/ruby-1.9.3-p385/lib/ruby/1.9.1/mkmf.rb:254:in `open' from /Users/radek/.rvm/rubies/ruby-1.9.3-p385/lib/ruby/1.9.1/mkmf.rb:280:in `postpone' from /Users/radek/.rvm/rubies/ruby-1.9.3-p385/lib/ruby/1.9.1/mkmf.rb:789:in `checking_for' from /Users/radek/.rvm/rubies/ruby-1.9.3-p385/lib/ruby/1.9.1/mkmf.rb:930:in `have_header' from extconf.rb:9:in `' Gem files will remain installed in /Users/radek/.rvm/gems/ruby-1.9.3-p385/gems/mysql2-0.3.16 for inspection. Results logged to /Users/radek/.rvm/gems/ruby-1.9.3-p385/gems/mysql2-0.3.16/ext/mysql2/gem_make.out An error occurred while installing mysql2 (0.3.16), and Bundler cannot continue. Make sure that `gem install mysql2 -v '0.3.16'` succeeds before bundling.
谢谢
在Ubuntu上，运行
sudo apt-get install libmysqlclient-dev
或者，如果您使用MariaDB，请运行
sudo apt-get install libmariadbclient-dev
在Gemfile中添加： –
gem 'mysql2', '0.3.16'
然后：-
bundle install
之后尝试： –
bundle update
看起来你的机器上没有安装mysql2 gem 。当你使用Mac OSX ，你应该像这样安装mysql2 gem
gem install mysql2 -- --with-mysql-dir=/usr/local/opt/mysql/
如果上述命令不起作用，请尝试这样做
sudo gem install mysql -- --with-mysql-config=/usr/local/mysql/bin/mysql_config
并尝试后
bundle install
这应该可以解决错误。
资源
我刚刚通过$ brew install mysql ，它解决了这个问题。
我最终得到了一个几乎相同的错误消息，试图在没有安装gcc-c++的机器上构建; mkmf无法编译一个简单的c程序，因为编译器没有编译。
如果你在CentOS上，你想要sudo yum install gcc-c++ 。 在Ubuntu上，它是sudo apt-get install g++ 。 旧版本的ruby-devel没有依赖于g++ ，这有点令人失望。