Bitcoin-qt v0.8.0b client on Mac OS X 10.8 crashes, why? I was running the stable 0.7.2 bitcoin-qt client (under OS X 10.8.2) for a couple of weeks, with the block-chain completely sync'ed on an ongoing basis. No transactions in my wallet.

I upgraded to the 0.8.0b release, and it spent a few hours reindexing the entire blockchain and catching up. So far so good.

0.8.0 client continued to run normally (launch, download / sync new blocks, etc.) for several days. 

Then, today, it crashes right after loading the wallet, but before it attempts any network connections. Crash is reproducible and persistent across reboots. Here's where the debug.log output ends. (No further errors.)

Bitcoin version v0.8.0-beta (2013-02-18 18:38:34 -0500)
...
init message: Verifying block database integrity...
Verifying last 288 blocks at level 3
No coin database inconsistencies in last 222481 blocks (8492 transactions)
block index            4479ms
init message: Loading wallet...
nFileVersion = 80000
wallet                 1500ms
init message: Importing blocks from block database...
I fixed the problem myself.  During a system sleep or perhaps a hang and hard reset (graceless shutdown) the block index got corrupted.  Best-practices for Bitcoin-qt, at least on a Mac, are probably to quit out of the app before putting the system to sleep.

To fix the problem, I trashed the entire directory

~/Library/Application Support/Bitcoing/chainstate/

and then relaunched the client. It re-indexed all the existing blocks (took about 2 hours,) but did not have to re-download the entire blockchain.

After allowing it to fully re-sync and catch up all blocks, I was able to do transactions normally. 48 hours later the client is still running stably and normally. (Including quitting &amp; re-starting the client.)