libc6 upgrade trouble due to dpkg/tar failures

["Ulf Jaenicke-Roessler" <ujr@physik.phy.tu-dresden.de>]

Hi,

 I had a strange problem today when I was upgrading libc6 from 2.2-10 to
 2.2.1-1. The system (in between potato and woody, complete upgrade in
 progress) was totally broken after libc6 was unpacked (during dpkg -i).

 I found that no symlink at all (i.e. libc.so.6, ld-linux.so.2, a.s.o.)
 existed. After creating all necessary links by hand using the rescue
 disk, ldconfig could not be run but instead it segfaulted.

 It turned out, that the deb was defective. dpkg --contents as well as
 tar showed errors. data.tar.gz was the culprit.

 I don't know how this could happen, the length of the file was correct,
 and it was transferred by apt-get to another system, installed there
 successfully, and then copied to a CD.
 However, I wonder what we can do to prevent such a mess.

 Maybe it would be useful, that dpkg puts md5sum's of control.tar.gz and
 data.tar.gz into the file debian-binary when the deb is built and checks
 these before unpacking? The md5sum in the Packages file cannot be used
 for installation with dpkg -i, obviously.

 Greetings,
  Ulf