Hi Marto, I tried to understand what system packages was modified using

sudo debsums --all --changed
[download]

and no system library or perl related packages seems to be altered..
I therefore decided to drop the perl lib directories on my home
As you kindly suggested I will install a deployment perl apart from system libreries using perlbrew which seems really cool, too lazy and fumbler to compile perl by myself.
The downside is having to reinstall all my code's dependencies, anyway not a big bother being a not-prolific programmer...
Furthermore I'm not sure if forcing a perl reinstallation with dpkg would mess other packages (the same package manager has perl dependencies), I will test it on a kvm guest as soon as possible.
thanks a lot for your help and time.

Luca