The breadboard.zip file from the tutorial in
http://arduino.cc/en/Tutorial/ArduinoToBreadboard contains only the file
boards.txt in the subfolder
breadboard.
This file is missing a line at the end to indicate the board variant:
atmega328bb.build.variant=standard
The subfolder must also contain the
standard variant with the corresponding
pins_arduino.h file.
So, follow the instructions in the tutorial to open your sketchbook folder and create the subfolder
\hardware\breadboard\ containing the file
boards.txt.
Then edit the file
boards.txt to add the missing line.
Then create a subfolder
\variants\standard\, and copy the file
pins_arduino.h from the folder
hardware\arduino\variants\standard\ in your Arduino IDE installation.
In Ubuntu 12.10 this is
\usr\share\arduino\ when the Arduino IDE is installed using the Ubuntu Software Center.
This will make the compilation work also for gnoduido.