A Note on Efficiency

Even though the cache appears to be a multi-dimensional object, it isn't.

Consider an expression like:

    $cache->{'perl-base'}{VersionList}[0]
            {DependsList}[0]{TargetPkg}{Name}

This creates a large number of temporary C++ objects, Perl objects to encapsulate them and lists thereof, so if you intend to access a bunch of attributes of an object it is best to store a copy of the intermediate object rather repeating the process for each attribute.

    my $v = $cache->{'perl-base'}{VersionList}[0]
                    {DependsList}[0];

    my $dep = $v->{TargetPkg}{Name};
    $dep .= " ($v->{CompTypeDeb} $v->{TargetVer})" if $v->{TargetVer};