package FOO::BAR;
BEGIN {::$INC{FOO/BAR.pm}=1};

##</code><code>##

{package mem; 
[#1] BEGIN{$::INC{'mem.pm'}=1}  #1: '#' present if in separate file
1}

##</code><code>##

{ package Dbg; 
  use mem &{sub(){$::INC{'Dbg.pm'}=1}};
  use warnings;
  use strict;
  our @EXPORT;
  our $FRE;
  use mem &{sub(){$FRE = qr{:([^:]+)$} } };
  use mem &{sub(){our @EXPORT = qw(Tracing Dumping Trackback DDump TPe) } };