A security upgrade released yesterday accidentally prevented the registry from serving ~200 very old packages whose package data was incomplete. These packages combined account for less than 0.02% of registry downloads, so their errors did not trigger our monitoring overnight.
Following user reports, we corrected the error this morning. The packages were unavailable for a period of ~14 hours, from 5pm PT 2015-07-04 to 7am PT 2015-08-05.
Even though the absolute numbers involved are small, the absence of these packages severely disrupted some users and we apologize. We are putting additional auditing into place around releases to ensure this kind of accident cannot occur in future.