How do you expect CPAN.pm to get past:
use Class::HPLOO::MakeMaker ;
to be able to run the code that tells it that it needs Class::HPLOO ?
I looked, and CPAN.pm parses the Makefile so you should try including a pre-built Makefile in your distribution (that will get replaced). I also checked CPANPLUS.pm and it also parses Makefiles to find prerequisites.
I don't know if including a Makefile will be enough to fix this problem, but you shouldn't just blithely blame the circular dependencies you've created with Class::HPLOO on "a bug in CPAN.pm".
Please uninstall your copy of Class::HPLOO, download your module(s) that use it from CPAN, and test that they install correctly.
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