Interestingly,... purging/re-installing cured the issue on one system, but on two others, installation fails:
# dpkg --configure -a Setting up debtags (2.1) ... Traceback (most recent call last): File "/usr/bin/debtags", line 25, in <module> import apt ImportError: No module named 'apt' dpkg: error processing package debtags (--configure): subprocess installed post-installation script returned error exit status 1 Errors were encountered while processing: debtags
smime.p7s
Description: S/MIME cryptographic signature