Fix Duplicate Sources List Entry Errors in Ubuntu 12.04 (Precise Pangolin)

Over the years we’ve shown you how to install many programs and packages in Ubuntu. We’ve shown you how to install packages via PPA, deb installer and from software repositories. Recently, we have receive many complaints about issues some of our readers are experiencing when updating their systems. One of the many issues is duplicate source.list entry error. When there are multiple source entries for a package in Ubuntu, everytime you try to update your system, you’ll get an error that says ‘duplicate source.list entry’. Because of that, it wouldn’t let you update your system until this problem is fixed. This brief tutorial is going to show you how to fix it in Ubuntu.