bin/largeprimes uses a custom shebang, which allows it to load modules from several locations: '..', '../lib', 'lib'. This could lead to load modules from an unpredictable location depending from where the script is run and what user is running it.
To install Crypt::Primes, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Crypt::Primes
CPAN shell
perl -MCPAN -e shell install Crypt::Primes
For more information on module installation, please visit the detailed CPAN module installation guide.