mysql2 gem fail to compile on os x lion - macos

Question

Configuration:
OS X Lion 10.7.5
XCode command line tools installed through xcode462_cltools_10_76938260a.dmg
MySQL installed through mysql-5.6.12-osx10.7-x86_64.dmg
ruby-1.9.3-p327 through rvm
Launching:
sudo env ARCHFLAGS="-arch x86_64" gem install mysql2 -- --with-mysql-dir=/usr/local/mysql --with-mysql-lib=/usr/local/mysql/lib --with-mysql-include=/usr/local/mysql/include --with-mysql-config=/usr/local/mysql/bin/mysql_config
The result is:
Building native extensions. This could take a while...
ERROR: Error installing mysql2:
ERROR: Failed to build gem native extension.
/Users/edo/.rvm/rubies/ruby-1.9.3-p327/bin/ruby extconf.rb --with-mysql-dir=/usr/local/mysql --with-mysql-lib=/usr/local/mysql/lib --with-mysql-include=/usr/local/mysql/include --with-mysql-config=/usr/local/mysql/bin/mysql_config
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/edo/.rvm/rubies/ruby-1.9.3-p327/include/ruby-1.9.1/ruby.h:32:
/Users/edo/.rvm/rubies/ruby-1.9.3-p327/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/edo/.rvm/rubies/ruby-1.9.3-p327/include/ruby-1.9.1/x86_64-darwin11.4.2/ruby/config.h:24:21: note: expanded from macro 'SIZEOF_LONG'
#define SIZEOF_LONG 8
and more.
Any suggestion?