Install libprefork-perl by entering the following commands in the terminal:
sudo apt update sudo apt install libprefork-perl
Module loading for forking or non-forking processes in Perl
The prefork pragma is intended to allow module writers to optimise module loading for both scenarios with as little additional code as possible. . prefork.pm is intended to serve as a central and optional marshalling point for state detection (the software is running in compile-time or run-time mode) and to act as a relatively light-weight module loader.