You can easily look for duplicates by:

• 📡 Going to the following website:

  https://bugs.launchpad.net/ubuntu/+source/[DESIRED PACKAGE'S NAME]/+bugs?field.status%3Alist=TRIAGED&field.status%3Alist=INPROGRESS&field.status%3Alist=FIXCOMMITTED

• 🔍 Then, by using the search functionality of your web-browser (by pressing the "Ctrl+F" key combination), looking for bugs with similar importance and title.

Duplicated bugs are those which describe exactly the same issue:

• 💣 Same cause.

• 🐾 Same steps to reproduce.

• 🔥 Same consequence.

When having to choose which duplicate to retain:

• 💟 Keep the one which is more descriptive.

• 🎁 Triage it as far as possible.