Can't store CODE items at blib/lib/Storable.pm

Either your object is a blessed CODE reference, or some property of your item may be holding a code reference. There's a big caveat about that in the documentation:

Passing unshared values between threads is accomplished by serializing the specified values using Storable when enqueuing and de-serializing the queued value on dequeuing. This allows for great flexibility at the expense of more CPU usage. It also limits what can be passed, as e.g. code references can not be serialized and therefore not be passed.

Update: I remembered that Storable does have some support for this, so there may be a workaround:

Since Storable version 2.05, CODE references may be serialized with the help of B::Deparse. To enable this feature, set $Storable::Deparse to a true value. To enable deserializazion, $Storable::Eval should be set to a true value. Be aware that deserialization is done through eval, which is dangerous if the Storable file contains malicious data. You can set $Storable::Eval to a subroutine reference which would be used instead of eval. See below for an example using a Safe compartment for deserialization of CODE references.