#!perl -w
...
use Foo::Bar;
...
{
 my $lastwarn = $SIG{__WARN__};
 # Filter out garbage warnings
 $SIG{__WARN__} = sub {
   return if ($_[0] =~ m/Use of uninitialized value in subroutine.*Foo\/Bar.*/);
   (defined($lastwarn) && $lastwarn) ? &$lastwarn(@_) : warn(@_);
 };
}