$ cp /usr/local/lib/x86_64-linux-gnu/perl/5.22.1/forks .
cp: omitting directory '/usr/local/lib/x86_64-linux-gnu/perl/5.22.1/forks'
$ perl -E 'BEGIN[unshift @INC, ".";} use forks'
Illegal declaration of subroutine BEGIN at -e line 1.