Errors Installing mysql2 gem via the Bundler

Question

I am trying to install the mysql2 gem via the Bundler, but it keeps dying with the following error:

** executing command /home/cc_rails/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/1.9.1/rubygems/installer.rb:483:in 'rescue in block in build_extensions':  ERROR: Failed to build gem native extension. (Gem::Installer::ExtensionBuildError)  /home/cc_rails/.rvm/rubies/ruby-1.9.2-p0/bin/ruby extconf.rb --with-mysql-config=/usr/bin/mysql_config checking for rb_thread_blocking_region()... yes checking for mysql.h... no checking for mysql/mysql.h... no  ----- mysql.h is missing.  please check your installation of mysql and try again. -----  *** 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=/home/cc_rails/.rvm/rubies/ruby-1.9.2-p0/bin/ruby --with-mysql-config Gem files will remain installed for inspection. 

Most things I found via Googling recommended passing the --with-mysql-config parameter to fix it. So, based on:

$ which mysql_config /usr/bin/mysql_config 

I added the following to the Bundler's config:

$ bundle config build.mysql2 --with-mysql-config='/usr/bin/mysql_config' 

However, still no luck -- same crash as above.

Since it's dying with the error mysql.h is missing, I checked for that, and it's allegedly around, just can't be found by the Bundler.

$ find / -name mysql.h /usr/include/mysql5/mysql/mysql.h 

Any thoughts?

Answer 1

Answer was similar to the one Wrikken posted -- here's what I did to fix it for the sake of future readers.

(This is for RHEL 5.5 -- similar but different commands apply for Ubuntu/Debian/etc.)

Doing sudo yum list installed will print out all installed packages on your machine (note: yum on RHEL requires you add a Red Hat Network repository [I use EPEL], and run it via sudo).

I had mysql and mysql-server, which explained why MySQL worked fine for every pre-existing app, but no mysql-devel, which is necessary to fix that mysql.h is missing error and similar other build errors.

Long story short, after a mysqldump -u root -ppassword --all-databases > full-dump.sql for safety, it was fixed with a simple

sudo yum install mysql-devel