Find where the eval warning is coming from:

#!/usr/bin/perl

use strict;
use warnings; # This directive causes Perl to warn you about dubious coding
use Carp ();

# This overrides the way warnings work, "cluck"ing so you know the
# call stack at the time of the eval
local $SIG{__WARN__} = &Carp::cluck;

sub greetings { print "Hello" }

eval 'sub greetings { print "Hi" }';

Changing the warning handler (the line local $SIG...etc) changes this:

$ ./s.pl
Subroutine greetings redefined at (eval 1) line 1.

To this:

$ ./s.pl
Subroutine greetings redefined at (eval 1) line 1.
        eval 'sub greetings { print "Hi" }
;' called at ./s.pl line 11