{
    package DEBUG;
    our $var = 'foo';
}

{
    package main;
    BEGIN { *var = \$DEBUG::var };
    print "Var is $var\n";
}

$ perl debug_begin.pl
Variable "$var" is not imported at debug_begin.pl line 14.
Global symbol "$var" requires explicit package name at debug_begin.pl line 14.
Execution of debug_begin.pl aborted due to compilation errors.
$ perl -v

This is perl, v5.8.9 built for x86_64-linux