ruby gem 安装mysql2_Ruby gem mysql2安装失败

当我尝试安装mysql2 gem时，它失败，没有明显的错误。有谁知道该怎么办才能解决此问题，以便安装mysql2？

$ sudo gem install mysql2

Building native extensions. This could take a while...

ERROR: Error installing mysql2:

ERROR: Failed to build gem native extension.

/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby extconf.rb

checking for rb_thread_blocking_region()... no

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

--without-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=/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/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 /Library/Ruby/Gems/1.8/gems/mysql2-0.2.6 for inspection.

Results logged to /Library/Ruby/Gems/1.8/gems/mysql2-0.2.6/ext/mysql2/gem_make.out