I experienced something new yesterday. Bitcoin can get corrupted, and I don't mean the political climate. I had a full sync done at block 439,321 and sometime later was moving block data over to the slower VPS system to test when I noticed that bitcoind was stopped. I mean I started it and a few seconds later it stopped itself. A short exploring of the debug.log showed me it had been corrupted some time before at block 439,395 and had been spewing log errors for a while. When I stopped bitcoind to move the data I had not noticed, and copied corrupt data over to the other system overwriting what was actually non-corrupted blocks. I guess one should always check the debug log before assuming it's in a healthy state. So, copy done, went to start again and seems bitcoind will run with errors but not start fresh with errors. Bam!
The problem with a pruned blockchain is that any corruption/failure means starting from block zero again. Ouch. Fortunately, since mysql data is detached from bitcoind data it was not affected and just has to wait for re-sync. And the bonus to a pruned blockchain, and my lesson for today, is that at only about 2GB it's not unwise to keep checkpoint copies of the bitcoin directory as a safe guard. If the chain is corrupted, then swap in a good recent one and catch up again. Corollary: check your backup debug.log to make sure your checkpoints aren't corrupted before rolling over.
I'm using this as an excuse for delaying my Full-Sync Report - I am working on it.