Because use is evaluated at compile-time you need to modify @INC before a given use statement is reached. Handily perl comes with the lib module to facilitate such @INC munging e.g

## this will modify @INC before the next 'use' statement
use lib "/home/user/scripts";

use kp1;
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Also note that I didn't use the lexical variable $dir as that will be declared at compile-time but won't be initialized until run-time (although you can get around this by using a BEGIN block).