Debian release files are now digitally signed. If the signature check
fails the apt tools will prompt to user who must enter "yes" to
proceed with the install. I have an older Etch release candidate
netinstall CD. It does not have the current Debian release signature
keys. While installing the packages the installer mysteriously
halted. Looking at the status log (alt-f4) I saw that aptitude was
waiting for the user to enter "yes" to proceed with the download and
install. It is a bug that the installer does not handle this which I
am guessing was fixed. Regardless I wanted to continue the install. I
tried typing "yes" in the installer but that did not work. I didn't
think it would. After some thought I opened the second console which
has a shell prompt. I ran the command:
echo Yes > /proc/pid_of_aptitude/fd/0
It worked. That is probably obvious to some of you, but I thought it
was pretty nifty.