estava a instalar o ruby-sqlite3 via gem, mas é-me reportado o seguinte output:

mathilda ~ # 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 install sqlite3-ruby
checking for fdatasync() in -lrt... no
checking for sqlite3.h... no

make
make: *** No rule to make target `ruby.h', needed by `sqlite3_api_wrap.o'. Stop.


Gem files will remain installed in /usr/lib/ruby/gems/1.8/gems/sqlite3-ruby-1.2.4 for inspection.
Results logged to /usr/lib/ruby/gems/1.8/gems/sqlite3-ruby-1.2.4/ext/sqlite3_api/gem_make.out

e tenho estes rpm's instalados:

mathilda ~ # rpm -qa | egrep 'sqlite'
python-sqlite-1.1.7-1.2.1
sqlite-devel-3.3.6-2
sqlite-3.3.6-2
mathilda ~ # rpm -qa | egrep '(ruby)|(irb)'
rubygem-rake-0.7.3-2.el5
ruby-irb-1.8.5-5.el5_2.5
rubygem-actionmailer-2.1.1-1.el5
ruby-libs-1.8.5-5.el5_2.5
ruby-devel-1.8.5-5.el5_2.5
ruby-ri-1.8.5-5.el5_2.5
rubygems-1.2.0-2.el5
rubygem-activeresource-2.1.1-1.el5
ruby-1.8.5-5.el5_2.5
ruby-rdoc-1.8.5-5.el5_2.5
rubygem-activesupport-2.1.1-1.el5
rubygem-activerecord-2.1.1-1.el5
rubygem-actionpack-2.1.1-1.el5
ruby-docs-1.8.5-5.el5_2.5
rubygem-rails-2.1.1-2.el5

e o sqlite3.h está no sistema.
mathilda ~ # find /usr/ -iname *sqlite3.h*
/usr/include/sqlite3.h

alguém sabe como resolver isto?