I just tried downloading 4 large part packs into a fresh install to see if I could get the issue to pop up (AIES, FASA, KW and NovaPunch). None of them were hosted on github, and I had no issues getting them down on the latest CKAN version. But then again, I tried the same with a bunch of mods hosted on github without error as well, and I expected that test to crash and burn. I know I've seen the error you mention before, and would love to try and hunt it down. Can you recall what you were trying to install/update the last time you had it?