fetchmail appears to be truncating large MIME attachments. I first noticed the problem when receiving a large jpeg. I've also tried receiving a zip attachment with similar results. Normal, small text and/or html emails work just fine. I noticed no errors when compiling or running fetchmail. I have to wonder, however, about "Applying fetchmail-6.2.5-fetchsizelimit.patch ..." seen when installing.
Well actually that patch is not causing the problem. I do not use fetchmail myself but this sounds to me like an upstream bug. Please reopen if you don't think it is. Cheers, Ferdy