contrib_guide.gsub!("aptitude", "apt-get")

It turns out aptitude has been removed from Ubuntu 10.10
and while you can manually install it, apt-get is the
blessed package manager. Google for "aptitude removed
from Ubuntu" for more details. Thanks to Rafael Mendonça
França for pointing this out.

railties/guides/source/contributing_to_ruby_on_rails.textile

@@ -67,13 +67,13 @@ The test suite must pass with any submitted code. No matter whether you are writ
 Install first libxml2 and libxslt together with their development files for Nokogiri. In Ubuntu that's
 
 <shell>
-sudo aptitude install libxml2 libxml2-dev libxslt1-dev
+sudo apt-get install libxml2 libxml2-dev libxslt1-dev
 </shell>
 
 Also, SQLite3 and its development files for the +sqlite3-ruby+ gem, in Ubuntu you're done with
 
 <shell>
-sudo aptitude install sqlite3 libsqlite3-dev
+sudo apt-get install sqlite3 libsqlite3-dev
 </shell>
 
 Get a recent version of "Bundler":http://gembundler.com/:
@@ -131,8 +131,8 @@ h5. MySQL and PostgreSQL
 To be able to run the suite for MySQL and PostgreSQL we need their gems. Install first the servers, their client libraries, and their development files. In Ubuntu just run
 
 <shell>
-sudo aptitude install mysql-server libmysqlclient15-dev
-sudo aptitude install postgresql postgresql-client postgresql-contrib libpq-dev
+sudo apt-get install mysql-server libmysqlclient15-dev
+sudo apt-get install postgresql postgresql-client postgresql-contrib libpq-dev
 </shell>
 
 After that run: