Hi Simon,
I noticed while browsing Debian Code Search that
this package creates /var/log/ikiwiki-hosting with debian/ikiwiki-hosting-web.dirs
This makes it piuparts compliant;
because piuparts does not actualy run the packages;
but I guess that after some real world usage of
this package there would be some files in this directory.
Please ensure that this directory is cleansed on purge.
This can be handled by a full blow .postrm script
or with a one-line (or two line if you also include /var/backups/ikiwiki-hosting-web/)
debian/ikiwiki-hosting-web.purge file & add a new dependecy on dh-sequence-cruft.
Greetings
Alexandre