To get a backtrace, follow the instructions on https://wiki.ubuntu.com/DebuggingProgramCrash. If your printer is not detected but the USB backend does not crash, see bug 872711.
To get a backtrace, follow the instructions on https:/ /wiki.ubuntu. com/DebuggingPr ogramCrash. If your printer is not detected but the USB backend does not crash, see bug 872711.