[Bitcoin-development] 0.8.2rc1 - testnet datadir behavior changed

Jay F jayf at outlook.com
Sun May 12 06:35:59 UTC 2013

On 5/10/2013 8:39 AM, Gavin Andresen wrote:
> Bitcoin-Qt version 0.8.2 release candidate 1 is now available from:
>    http://sourceforge.net/projects/bitcoin/files/Bitcoin/bitcoin-0.8.2/test/

Testnet glitch, something broke...

Fired up 0.8.2rc, and .... where's the coins? Where's the blocks?

I get a new empty datadir/testnet3 subdirectory.

bitcoin-qt.exe -datadir=c:\testnet (with a testnet=1 bitcoin.conf file 
option in that directory) stored wallet/blocks/chainstate in the root 
with previous versions. Now the root datadir data is ignored (except the 
config file) and a new hierarchy was created in subdirectory 

So what's happening?

This looks to be done by https://github.com/bitcoin/bitcoin/issues/2605 
... after searching the code for the change and then finding the commit.

1 day from opened to committed, released six days later... no changelog.

The datadir previously worked as I expected with both bitcoin-qt and 
bitcoind interacting with no problems, when simply specifying a 
command-line datadir, so I don't see the bug.

I can see how the previous behavior might be dangerous if the config 
file was removed. I just did that, and there's a cool freakout where my 
testnet wallet balance looks like real BTC and Bitcoin tries to reorg 
67662 blocks starting from the genesis block. After receiving real block 
73354 per debug log, a nice unrecoverable crash:

"Assertion failed!"
File: src/main.cpp Line 1745
Expression: pfork != NULL

This needs to be added to the changelog, since dropping in this binary 
will break testnet stuff if anybody is using Bitcoin this way for their 
testnet faucet, etc:

" * testnet data now stored in testnet3 subdirectory, enforced even when 
specifying datadir on command line (manually move your data first)"

More information about the bitcoin-dev mailing list