In upgrading to 15.04 the install broke on installing clamav.
It didn’t affect the upgrade but clamav was no longer installed. On running it manually I got the following error
error /var/lib/dpkg/info/clamav-daemon.postinst: 626: /var/lib/dpkg/info/clamav-daemon.postinst: cannot create : Directory nonexistent
It seems that there is a typo in the file /var/lib/dpkg/info/clamav-daemon.postinst.
On line 626 replace $DEBCONFILE with $DEBCONFFILE
Save and re-run apt-get install clamav