Soy nuevo en RoR y estoy intentando instalar Mysql2 -v '0.3.11'. Tengo OS X Mountain Lion, rieles 3.2.6, rubí 1.9.3.

A continuación se muestra el error que recibo. Miré por todas partes y no encontré nada.

$gem install mysql2 -v '0.3.11'
Building native extensions.  This could take a while...
ERROR:  Error installing mysql2:
ERROR: Failed to build gem native extension.

    /Users/curiosity/.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.h... yes
checking for errmsg.h... yes
checking for mysqld_error.h... yes
creating Makefile

make
compiling client.c
In file included from client.c:1:
In file included from ./mysql2_ext.h:8:
In file included from /Users/curiosity/.rvm/rubies/ruby-1.9.3-p125/include/ruby-1.9.1/ruby.h:32:
/Users/curiosity/.rvm/rubies/ruby-1.9.3-p125/include/ruby-1.9.1/ruby/ruby.h:105:37:     error: 'ruby_check_sizeof_long' declared as an array with a negative size
typedef char ruby_check_sizeof_long[SIZEOF_LONG == sizeof(long) ? 1 : -1];
                                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Users/curiosity/.rvm/rubies/ruby-1.9.3-p125/include/ruby-1.9.1/x86_64-darwin12.0.0/ruby/config.h:24:21: note: expanded from macro 'SIZEOF_LONG'
#define SIZEOF_LONG 8
                ^
In file included from client.c:1:
In file included from ./mysql2_ext.h:8:
In file included from /Users/curiosity/.rvm/rubies/ruby-1.9.3-p125/include/ruby-1.9.1/ruby.h:32:
/Users/curiosity/.rvm/rubies/ruby-1.9.3-p125/include/ruby-1.9.1/ruby/ruby.h:109:38: error: 'ruby_check_sizeof_voidp' declared as an array with a negative size
typedef char ruby_check_sizeof_voidp[SIZEOF_VOIDP == sizeof(void*) ? 1 : -1];
                                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Users/curiosity/.rvm/rubies/ruby-1.9.3-p125/include/ruby-1.9.1/x86_64-darwin12.0.0/ruby/config.h:28:22: note: expanded from macro 'SIZEOF_VOIDP'
#define SIZEOF_VOIDP 8
                 ^
In file included from client.c:1:
In file included from ./mysql2_ext.h:8:
In file included from /Users/curiosity/.rvm/rubies/ruby-1.9.3-p125/include/ruby-1.9.1/ruby.h:32:
In file included from /Users/curiosity/.rvm/rubies/ruby-1.9.3-p125/include/ruby-1.9.1/ruby/ruby.h:1377:
In file included from /Users/curiosity/.rvm/rubies/ruby-1.9.3-p125/include/ruby-1.9.1/ruby/intern.h:34:
/Users/curiosity/.rvm/rubies/ruby-1.9.3-p125/include/ruby-1.9.1/ruby/st.h:67:45: error: 'st_check_for_sizeof_st_index_t' declared as an array with a negative size
typedef char st_check_for_sizeof_st_index_t[SIZEOF_VOIDP == (int)sizeof(st_index_t) ? 1 : -1];
                                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Users/curiosity/.rvm/rubies/ruby-1.9.3-p125/include/ruby-1.9.1/x86_64-darwin12.0.0/ruby/config.h:28:22: note: expanded from macro 'SIZEOF_VOIDP'
#define SIZEOF_VOIDP 8
                 ^
3 errors generated.
make: *** [client.o] Error 1


Gem files will remain installed in /Users/curiosity/.rvm/gems/ruby-1.9.3-p125/gems/mysql2-0.3.11 for inspection.
Results logged to /Users/curiosity/.rvm/gems/ruby-1.9.3-p125/gems/mysql2-0.3.11/ext/mysql2/gem_make.out

Gracias por tu ayuda.