I took a quick look at the source, this code is what is responsible for incorrectly turning auto/libwww/perl/.packlist into libwww/perl.pm. Personally I'd consider this a bug, or at least a "limitation" that occurrs when the location of the .packlist file(s) don't match the module names (but rather the distribution names). This appears to be true of the four modules named in this node, and if one were to analyze the other ~38k CPAN distros, I'm sure there's more out there.