I was looking for the Chromium web browser and installed this mysterious chromium-bsu package at the suggestion of the package manager:
mike@mikebox:~$ sudo apt-get install chromium ... Package chromium is not available, but is referred to by another package. ... However the following packages replace it: chromium-bsu
All the most important discoveries were made by accident — including penicillin, teflon, coke, and what turned out to be a really cool space-shooter game.
About an hour of clicking later— back to work. Installing the wrong package is a real time sink!