use warnings;
use strict;
package My::Mod;
use File::Spec;
use Carp;
my $module = File::Spec->catfile(split('::', __PACKAGE__));
my $modPath;
for (@INC) {
    my $t = File::Spec->catfile($_, $module);
    if ( -e $t ) {
        $modPath = $t;
        last;
    }
}
my $configPath = $modPath;
if ($modPath) {
    $configPath =~ s/\.pm$/.yml/;
}
else {
    croak("Can't find config file.");
}