In response to CPAN and "Weak references", I had recommended Task::Weaken. Building upon Task::Weaken, I put this list together to ensure that my system would be able to handle weak references:

#!/usr/local/bin/perl use strict; use warnings; use CPAN; CPAN::Shell->install( "Task::Weaken", "Cache::Weak", "Class::WeakSingleton", "Convert::Scalar", "Data::Structure::Util", "Devel::Cycle", "Devel::Monitor", "Devel::Peek", "EO::WeakArray", "Hash::NoRef", "IO::Plumbing", "Scalar::Util", "Set::Object", "Test::Memory::Cycle", "Test::NoXS", "Test::Weaken", "Tie::RefHash", "Tie::Util", "WeakRef", "WeakRef::Auto");