BEGIN {
  use B::Utils qw(opgrep walkallops_filtered);
  walkallops_filtered (
    # Search for pack() with a constant first arg
    sub { opgrep( { name => 'pack',
                    first => { name => 'const' }
                  }
                )
        },
    sub { my $pack = shift;
          my $const = $pack->first;

          # Disallow p and P
          if ($const->pv =~ m/p/i)
            {
              die "Format p or P was used in pack"
            }
        }
    
  );
}