Comment 5 for bug 202009

 $ echo "get debconf/frontend" | debconf-communicate
 0 Dialog

This is not DEBIAN_FRONTEND; I'm looking for the value of the DEBIAN_FRONTEND environment variable here, which overrides whatever frontend setting is stored in debconf itself.

The expected behavior is that when you run update-grub (as part of a package install or otherwise) and there are local changes in your menu.lst relative to the last auto-generated menu.lst, you get a debconf prompt asking you how to resolve this conflict.

Of course, once this conflict has been resolved for a given iteration of the menu.lst, you won't be asked again until the proposed menu.lst settings change. So if you had DEBIAN_FRONTEND=noninteractive set when you *last* upgraded, running update-grub again will not give you a new prompt. To force the prompt to be shown, you can adjust one of the settings in your kopt_2_6 line and re-run update-grub.