$ cat Foo.pm
use strict;
use warnings;
package Foo;
use Carp qw/ croak /;

sub foo {
    eval {
        Baz::bar();
    };
    my $e = $@;
    print "\$\@ = '$e'\n";
    $e =~ s/(.*) at .*\n/$1/;
    croak $e;
}

package Baz;

sub bar {
    die "blubb";
}

1;
$ perl -wle'
use Foo;
Foo::foo();'
$@ = 'blubb at Foo.pm line 19.
'

blubb at -e line 3