Issue with 'gem install sqlite3-ruby' on RHEL6

I'm attempting to install Ruby on Rails 3 on RHEL 6. I've 'yum install' sqlite and sqlite-devel (which is sqlite3 on RHEL6). As you can see, sqlite3.h does exist where it needs to be. 'gem install sqlite3-ruby' still doesn't work, for some reason.

SQLite3:

[root@rhel6base gems]# yum list sqlite-devel
Installed Packages
sqlite-devel.x86_64            3.6.20-1.el6            @local
Available Packages
sqlite-devel.i686              3.6.20-1.el6            local 

[root@rhel6base gems]# ls -l /usr/include/sqlite3.h
-rw-r--r--. 1 root root 268966 Nov 24  2009 /usr/include/sqlite3.h

Gem install:

[root@rhel6base gems]# gem install sqlite3-ruby
Building native extensions.  This could take a while...
ERROR:  Error installing sqlite3-ruby:
    ERROR: Failed to build gem native extension.

        /usr/bin/ruby extconf.rb
checking for sqlite3.h... no
sqlite3.h is missing. Try 'port install sqlite3 +universal'
or 'yum install sqlite3-devel' and check your shared library search path (the
location where your sqlite3 shared library is located).
*** 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=/usr/bin/ruby
    --with-sqlite3-dir
    --without-sqlite3-dir
    --with-sqlite3-include
    --without-sqlite3-include=${sqlite3-dir}/include
    --with-sqlite3-lib
    --without-sqlite3-lib=${sqlite3-dir}/lib


Gem files will remain installed in /usr/lib64/ruby/gems/1.8/gems/sqlite3-1.3.3 for inspection.
Results logged to /usr/lib64/ruby/gems/1.8/gems/sqlite3-1.3.3/ext/sqlite3/gem_make.out

PS: It'd sure be nice to create a 'rhel6' tag, but I don't have enough reputation.

Solution

It turns out you have to have gcc installed for 'gem install sqlite3-ruby' to work. It will never explicitly tell you that gcc isn't found (even the log file doesn't mention it).