bitcoin/doc/release-notes.md

(note: this is a temporary file, to be added-to by anybody, and moved to release-notes at release time)

Bitcoin Core version version is now available from:

https://bitcoincore.org/bin/bitcoin-core-*version*/

This is a new major version release, including new features, various bugfixes and performance improvements, as well as updated translations.

Please report bugs using the issue tracker at GitHub:

https://github.com/bitcoin/bitcoin/issues

To receive security and update notifications, please subscribe to:

https://bitcoincore.org/en/list/announcements/join/

How to Upgrade

If you are running an older version, shut it down. Wait until it has completely shut down (which might take a few minutes for older versions), then run the installer (on Windows) or just copy over /Applications/Bitcoin-Qt (on Mac) or bitcoind/bitcoin-qt (on Linux).

The first time you run version 0.15.0, your chainstate database will be converted to a new format, which will take anywhere from a few minutes to half an hour, depending on the speed of your machine.

Note that the block database format also changed in version 0.8.0 and there is no automatic upgrade code from before version 0.8 to version 0.15.0. Upgrading directly from 0.7.x and earlier without redownloading the blockchain is not supported. However, as usual, old wallet versions are still supported.

Downgrading warning

The chainstate database for this release is not compatible with previous releases, so if you run 0.15 and then decide to switch back to any older version, you will need to run the old release with the -reindex-chainstate option to rebuild the chainstate data structures in the old format.

If your node has pruning enabled, this will entail re-downloading and processing the entire blockchain.

Compatibility

Bitcoin Core is extensively tested on multiple operating systems using the Linux kernel, macOS 10.8+, and Windows 7 and newer (Windows XP is not supported).

Bitcoin Core should also work on most other Unix-like systems but is not frequently tested on them.

Notable changes

RPC changes

Low-level changes

• The createrawtransaction RPC will now accept an array or dictionary (kept for compatibility) for the outputs parameter. This means the order of transaction outputs can be specified by the client.
• The fundrawtransaction RPC will reject the previously deprecated reserveChangeKey option.
• Wallet getnewaddress and addmultisigaddress RPC account named parameters have been renamed to label with no change in behavior.
• Wallet getlabeladdress, getreceivedbylabel, listreceivedbylabel, and setlabel RPCs have been added to replace getaccountaddress, getreceivedbyaccount, listreceivedbyaccount, and setaccount RPCs, which are now deprecated. There is no change in behavior between the new RPCs and deprecated RPCs.
• Wallet listreceivedbylabel, listreceivedbyaccount and listunspent RPCs add label fields to returned JSON objects that previously only had account fields.
• sendmany now shuffles outputs to improve privacy, so any previously expected behavior with regards to output ordering can no longer be relied upon.

External wallet files

The -wallet=<path> option now accepts full paths instead of requiring wallets to be located in the -walletdir directory.

Newly created wallet format

If -wallet=<path> is specified with a path that does not exist, it will now create a wallet directory at the specified location (containing a wallet.dat data file, a db.log file, and database/log.?????????? files) instead of just creating a data file at the path and storing log files in the parent directory. This should make backing up wallets more straightforward than before because the specified wallet path can just be directly archived without having to look in the parent directory for transaction log files.

For backwards compatibility, wallet paths that are names of existing data files in the -walletdir directory will continue to be accepted and interpreted the same as before.

Low-level RPC changes

• When bitcoin is not started with any -wallet=<path> options, the name of the default wallet returned by getwalletinfo and listwallets RPCs is now the empty string "" instead of "wallet.dat". If bitcoin is started with any -wallet=<path> options, there is no change in behavior, and the name of any wallet is just its <path> string.

Logging

• The log timestamp format is now ISO 8601 (e.g. "2018-02-28T12:34:56Z").

Miner block size removed

The -blockmaxsize option for miners to limit their blocks' sizes was deprecated in V0.15.1, and has now been removed. Miners should use the -blockmaxweight option if they want to limit the weight of their blocks' weights.

Python Support

Support for Python 2 has been discontinued for all test files and tools.

Credits

Thanks to everyone who directly contributed to this release:

As well as everyone that helped translating on Transifex.