Bug#455974: libc6: Upgrade to libc 2.7-3 breaking of dpkg
Similar to the OP, but perhaps somewhat different also. Recent upgrade
to libc6 2.7-3 borked dpkg, which then reported libc6 was not completely
The error message complained about the /var/lib/dpkg/info/libc6.postinst
script, so I renamed the script temporarily, and ran dpkg-reconfigure libc6.
This forced libc6 to install, but a couple of other packages also then
failed, with similar /var/lib/dpkd/info postinst script complaints
Fix was to reconfigure dpkg to use dialog frontend, using the f switch, as:
# dpkg-reconfigure -f dialog
I then renamed the various /var/lib/dpkg/info scripts back to the
original nomenlature, and ran dpkg-reconfigure on the offending packages
Apologies if this is not the same problem, but since it occurred with
libc6 upgrade, I thought it might be relevant.