./perl -MDerp::Derp
Can't locate Derp/Derp.pm in @INC

See: perldoc -v @INC

You may need to install the Derp::Derp module:
https://metacpan.org/search?q=Derp::Derp

@INC entries checked:

  /home/marto/localperl/lib/site_perl/5.42.0/x86_64-linux
  /home/marto/localperl/lib/site_perl/5.42.0
  /home/marto/localperl/lib/5.42.0/x86_64-linux
  /home/marto/localperl/lib/5.42.0.
BEGIN failed--compilation aborted.

~/localperl/bin