It sounds like eppo has broken the perl install on his system too much for that to work.

As others have said, it is usualy not a good idea to modify the system perl install. This applies double on Debian derived distros such as Ubuntu, because the system package manager uses perl internaly, so if you break perl you are likey to break the whole system to the point that it is impossible to re-install perl (or anything else), forcing you to re-instal the whole system to get it working again.