Installing anything over a symlink opens a can of worms -
this causes problems on upgrades while switching between directory and symlink
or if the symlink is ever changed.
Piuparts looks at all $pathname known to dpkg and checks for
$(dirname $pathname) != $(readlink $(dirname $pathname))
The commandline to find these logs is:
COMMAND='grep -E "silently overwrites files via directory symlinks|installs objects over existing directory symlinks|dirname part contains a symlink"'