错误:无法构建gem本机扩展(mysql2 on rails 3.2.3)

Question

我正在尝试使用Rails 3.2.3安装mysql2 gem，但失败了：

★  bundle install
Fetching gem metadata from https://rubygems.org/.........
Using rake (0.9.2.2) 
Using i18n (0.6.0) 
Using multi_json (1.2.0) 
Using activesupport (3.2.3) 
Using builder (3.0.0) 
Using activemodel (3.2.3) 
Using erubis (2.7.0) 
Using journey (1.0.3) 
Using rack (1.4.1) 
Using rack-cache (1.2) 
Using rack-test (0.6.1) 
Using hike (1.2.1) 
Using tilt (1.3.3) 
Using sprockets (2.1.2) 
Using actionpack (3.2.3) 
Using mime-types (1.18) 
Using polyglot (0.3.3) 
Using treetop (1.4.10) 
Using mail (2.4.4) 
Using actionmailer (3.2.3) 
Using arel (3.0.2) 
Using tzinfo (0.3.32) 
Using activerecord (3.2.3) 
Using activeresource (3.2.3) 
Using bundler (1.1.3) 
Using coffee-script-source (1.2.0) 
Using execjs (1.3.0) 
Using coffee-script (2.2.0) 
Using rack-ssl (1.3.2) 
Using json (1.6.6) 
Using rdoc (3.12) 
Using thor (0.14.6) 
Using railties (3.2.3) 
Using coffee-rails (3.2.2) 
Using jquery-rails (2.0.2) 
Installing mysql2 (0.3.11) with native extensions 
Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.

        /Users/rarneson/.rvm/rubies/ruby-1.9.3-p125/bin/ruby extconf.rb 
checking for rb_thread_blocking_region()... yes
checking for rb_wait_for_single_fd()... yes
checking for mysql_query() in -lmysqlclient... no
checking for main() in -lm... yes
checking for mysql_query() in -lmysqlclient... no
checking for main() in -lz... yes
checking for mysql_query() in -lmysqlclient... no
checking for main() in -lsocket... no
checking for mysql_query() in -lmysqlclient... no
checking for main() in -lnsl... no
checking for mysql_query() in -lmysqlclient... no
checking for main() in -lmygcc... no
checking for mysql_query() in -lmysqlclient... no
*** 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/rarneson/.rvm/rubies/ruby-1.9.3-p125/bin/ruby
    --with-mysql-config
    --without-mysql-config
    --with-mysql-dir
    --without-mysql-dir
    --with-mysql-include
    --without-mysql-include=${mysql-dir}/include
    --with-mysql-lib
    --without-mysql-lib=${mysql-dir}/lib
    --with-mysqlclientlib
    --without-mysqlclientlib
    --with-mlib
    --without-mlib
    --with-mysqlclientlib
    --without-mysqlclientlib
    --with-zlib
    --without-zlib
    --with-mysqlclientlib
    --without-mysqlclientlib
    --with-socketlib
    --without-socketlib
    --with-mysqlclientlib
    --without-mysqlclientlib
    --with-nsllib
    --without-nsllib
    --with-mysqlclientlib
    --without-mysqlclientlib
    --with-mygcclib
    --without-mygcclib
    --with-mysqlclientlib
    --without-mysqlclientlib


Gem files will remain installed in /Users/rarneson/.rvm/gems/ruby-1.9.3-p125/gems/mysql2-0.3.11 for inspection.
Results logged to /Users/rarneson/.rvm/gems/ruby-1.9.3-p125/gems/mysql2-0.3.11/ext/mysql2/gem_make.out
An error occured while installing mysql2 (0.3.11), and Bundler cannot continue.
Make sure that `gem install mysql2 -v '0.3.11'` succeeds before bundling.

我正在运行bundle install，它在我的Gemfile中：

gem 'mysql2', '~> 0.3.11' 

我目前已经通过MAMP运行了MySQL。我不确定这是不是一个坏主意，我应该运行一个普通的MySQl，但我目前的问题似乎只是安装gem。我在stackoverflow上见过很多这样的问题，但看起来都有点不同，或者都有非常复杂的解决方案。我是不是漏掉了什么？一些简单的东西？做些愚蠢的事？如果需要，我可以从out文件中提供其他信息。我读到过一些人在开发时使用SQLite，然后在prod中使用MySQL进行测试，但这听起来是一个非常可怕的想法。

Answer 1

我最终只安装了一个新的MySQL副本，没有使用MAMP，这就起到了作用。还必须确保安装的是64位版本，而不是32位版本。

Answer 2

来自https://github.com/brianmario/mysql2/issues/8

刚在控制台里复制了这个

sudo apt-get install mysql-client libmysqlclient-dev

成功了！！

Answer 3

我使用Homebrew for Mac安装mysql：

brew install mysql

然后我使用gem命令安装mysql2 gem：

sudo gem install mysql2