====== Ubuntu - Packages - Automatically installed packages ======

Sometimes packages are installed automatically on the system because some other package recommends it, but they are not actually dependencies of packages:

To know why an automatically installed package is present on the system, issue the command:

<code bash>
aptitude why package_name
</code>

result:

<code bash>
i   aptitude         Recommends apt-xapian-index         
i A apt-xapian-index Depends    python-debian (>= 0.1.15)
</code>

----

In contrast, **why-not** finds a dependency chain leading to a conflict with the target package:

<code bash>
aptitude why-not package_name
</code>

result:

<code bash>
i ocaml-core            Depends   ocamlweb
i A ocamlweb            Depends   tetex-extra
i A texlive-latex-extra Conflicts textopo
</code>