Specify the whole path as "lib", and only the file as "required". As use executes at compile time, be sure to set the variables in a BEGIN block: 
my ($codes_dir, $runner_lib);
BEGIN {
    $codes_dir  = '...';
    $runner_lib = '...';
}
use lib "$codes_dir/perl_libs", "$runner_lib/runner_libs";
require 'perl_db_interface.pl';
require 'CodesModule.pm';

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Note that normally, you shouldn't require files but packages: 

require CodesModule;

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Why don't you use them directly, anyway? 

($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord
}map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,

[download]

In reply to Re: Using Multiple Modules by choroba
in thread Using Multiple Modules by hmeharward

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