size of array ruby_check_sizeof_long is negative in case of installing mysql2 gem

March 16, 2013

When you install mysql2 with gem, if you ran into a weird issue such as error: size of array ‘ruby_check_sizeof_long’ is negative, it must be caused by the arch of mysql binary you installed.

ERROR:  Error installing mysql2:
        ERROR: Failed to build gem native extension.

        /Users/tsakuma/.rvm/rubies/ruby-1.9.3-p327/bin/ruby extconf.rb --with-mysql-config=~/.kiidev/usr/mysql-5.5.28-osx10.6-x86/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 /Users/tsakuma/.rvm/rubies/ruby-1.9.3-p327/include/ruby-1.9.1/ruby.h:32,
                 from ./mysql2_ext.h:8,
                 from client.c:1:
/Users/tsakuma/.rvm/rubies/ruby-1.9.3-p327/include/ruby-1.9.1/ruby/ruby.h:105: error: size of array ‘ruby_check_sizeof_long’ is negative
/Users/tsakuma/.rvm/rubies/ruby-1.9.3-p327/include/ruby-1.9.1/ruby/ruby.h:109: error: size of array ‘ruby_check_sizeof_voidp’ is negative
In file included from /Users/tsakuma/.rvm/rubies/ruby-1.9.3-p327/include/ruby-1.9.1/ruby/intern.h:34,
                 from /Users/tsakuma/.rvm/rubies/ruby-1.9.3-p327/include/ruby-1.9.1/ruby/ruby.h:1382,
                 from /Users/tsakuma/.rvm/rubies/ruby-1.9.3-p327/include/ruby-1.9.1/ruby.h:32,
                 from ./mysql2_ext.h:8,
                 from client.c:1:
/Users/tsakuma/.rvm/rubies/ruby-1.9.3-p327/include/ruby-1.9.1/ruby/st.h:67: error: size of array ‘st_check_for_sizeof_st_index_t’ is negative
lipo: can't open input file: /var/folders/nh/0mswhyh930737hfwj9xqbzp40000gn/T//ccjcncjn.out (No such file or directory)
make: *** [client.o] Error 1


Gem files will remain installed in /Users/tsakuma/.rvm/gems/ruby-1.9.3-p327/gems/mysql2-0.3.11 for inspection.
Results logged to /Users/tsakuma/.rvm/gems/ruby-1.9.3-p327/gems/mysql2-0.3.11/ext/mysql2/gem_make.out

Download a new archive from the download page.

So you start installing again like:

gem install mysql2 --no-ri --no-rdoc -- --with-mysql-config=$YOUR_MYSQL_HOME/bin/mysql_config
Successfully installed mysql2-0.3.11
1 gem installed

The answer on the Stack Overflow was helpful for me.