MySQL Install: ERROR: Failed to build gem native extension

I'm trying to get MySQL installed to the latest version due to some installation going wrong somewhere along the line. I run the command gem install mysql and I receive the following:

Building native extensions. This
could take a while… ERROR: Error
installing mysql: ERROR: Failed to
build gem native extension.

/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby
extconf.rb extconf.rb:4: warning:
Insecure world writable dir /usr/bin
in PATH, mode 040777 extconf.rb:4:
warning: Insecure world writable dir
/usr/bin in PATH, mode 040777
extconf.rb:7: warning: Insecure world
writable dir /usr/bin in PATH, mode
040777 mkmf.rb can't find header files
for ruby at
/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/ruby.h

Gem files will remain installed in
/Library/Ruby/Gems/1.8/gems/mysql-2.8.1
for inspection. Results logged to
/Library/Ruby/Gems/1.8/gems/mysql-2.8.1/ext/mysql_api/gem_make.out

I've searched, and tried a whole host of things, from installing specific versions to trying to reinstall ruby without any luck.

Any ideas where I may be going wrong?

I'm trying to get MySQL installed to the latest version due to some installation going wrong somewhere along the line. I run the command gem install mysql and I receive the following:

Building native extensions. This
could take a while… ERROR: Error
installing mysql: ERROR: Failed to
build gem native extension.

/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby
extconf.rb extconf.rb:4: warning:
Insecure world writable dir /usr/bin
in PATH, mode 040777 extconf.rb:4:
warning: Insecure world writable dir
/usr/bin in PATH, mode 040777
extconf.rb:7: warning: Insecure world
writable dir /usr/bin in PATH, mode
040777 mkmf.rb can't find header files
for ruby at
/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/ruby.h

Gem files will remain installed in
/Library/Ruby/Gems/1.8/gems/mysql-2.8.1
for inspection. Results logged to
/Library/Ruby/Gems/1.8/gems/mysql-2.8.1/ext/mysql_api/gem_make.out

I've searched, and tried a whole host of things, from installing specific versions to trying to reinstall ruby without any luck.

Any ideas where I may be going wrong?

EDIT: I installed XCode off my Snow Leopard DVD and the error just changed slightly to the following:

Building native extensions. This could take a while…
ERROR: Error installing mysql:
ERROR: Failed to build gem native extension.

/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby extconf.rb
extconf.rb:4: warning: Insecure world writable dir /usr/bin in PATH, mode 040777
extconf.rb:4: warning: Insecure world writable dir /usr/bin in PATH, mode 040777
extconf.rb:7: warning: Insecure world writable dir /usr/bin in PATH, mode 040777
extconf.rb:17: warning: Insecure world writable dir /usr/bin in PATH, mode 040777
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/mysql-2.8.1 for inspection.
Results logged to /Library/Ruby/Gems/1.8/gems/mysql-2.8.1/ext/mysql_api/gem_make.out

doing "which mysql" on the command line returns nothing, which means it's not recognizing it. I also installed the MySQL system preferences option, and I can't stop MySQL from running. Now I'm completely stuck as what to do!

EDIT EDIT

I've just completely reinstalled MySQL using this guide http://hivelogic.com/articles/installing-mysql-on-mac-os-x

Unfortunately this didn't work either, I still receive the same errors. I can't even do mysql -uroot at the command line, I get the error of:

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)

So I think I've tried everything.

**SOLVED*

Sorry guys, the reason for this not working was because of the MySQL paths. I've blogged on it here: http://www.kieransenior.co.uk/2010/02/mysql-cant-connect-using-ruby-on-rails-mac-os-x-snow-leopard/