Release Notes for Bitcoin Cash Node version 22.1.0

Bitcoin Cash Node version 22.1.0 is now available from:


This is a minor release of Bitcoin Cash Node that implements some interface enhancements and includes a number of other corrections and improvements.

Users who are running any of our previous releases are recommended to upgrade to v22.1.0 ahead of November 2020.

We remind that the 0.21.x family of BCHN releases does not implement the new rules for the coming November 2020 upgrade. Users must upgrade to a release in the 22.x family before November 15th, 2020.

Usage recommendations

Installing this version is optional, but we recommend that users of 22.0.0 upgrade to this minor release for the corrections contained in it.

This update is compatible with the November 15, 2020 Bitcoin Cash network upgrade.

Network changes

New test network options.

This release delivers the ability to access two new test networks:

  • testnet4 (more lightweight test network to be kept spam-free)
  • scalenet (for high-throughput tests, including at block sizes beyond current main network maximum)

Please refer to doc/ or for further information.

New seeder configuration

Added configuration to access new DNS seeders from and a new mainnet seeder.

  • (mainnet)
  • (mainnet)
  • (testnet3)
  • (testnet4)
  • (scalenet)

Removed the defunct seeder entry

Added functionality


This release implements the 'extversion' extended versioning handshake protocol (ref. BCHN merge requests !558 and !753), previously implemented by Bitcoin Unlimited. We thank Greg Griffith and the Bitcoin Unlimited developers for their efforts to achieve this implementation in BCHN.

The extversion handshaking is disabled by default and can be enabled using the -useextversion CLI argument or the useextversion=1 configuration file setting.

Nodes indicate extversion support by setting service bit 11 (EXTVERSION).

Right now the BCHN implementation of ExtVersion supports only 1 key -- the "Version" key.

The specification can be found in doc/ or at .


A new indexdir configuration option allows the user to specify a path under which the leveldb 'index' folder is stored.

The use case for this new option is to store the index on a separate volume of faster access media while the blocks can be stored on slower media.

If the argument is not specified, the index is stored in the usual place (in the blocks/index/ folder).


A new finalizeheaders configuration option (enabled by default) rejects block headers which are below the finalized block height (if a block has indeed been finalized already).

Finalized blocks are not supposed to be re-organized under any circumstances (just like checkpointed blocks). There is therefore no need to accept headers for alternate chains below the last finalized block.

Nodes which submit such blocks are penalized according to a penalty score determined by the finalizeheaderspenalty option (default is 100, meaning such nodes will be disconnected).

In practice this works to quickly disconnect nodes from old chains like the "Clashic" network which sometimes submit headers of forked off chains with vastly lower block heights.

New debugging tracepoints

Two new debugging tracepoints have been added:

  • debug=finalization
  • debug=parking

These can be used to log events related to automatic finalization and parking/unparking.

Deprecated functionality

No functionality is deprecated in this release.

Removed functionality

No functionality is removed in this release.

New RPC methods

No new RPC methods are added in this release, however some argument aliases are added to existing calls (for backward compatibility) and a new optional parameter is added to the sendtoaddress method (for improved coin selection performance).

Low-level RPC changes

An optional coin selection ('coinsel') argument has been added to the sendtoaddress RPC method.

An alias blockhash has been added for the hash_or_height parameter of the getblockheader call, for backward compatibility.

An alias dummy has been added for the parameters argument of the submitblock call, for backward compatibility.


Bitcoin Cash Node 22.1.0 does not introduce any known regressions compared to 22.0.0.

Known Issues

Some issues could not be closed in time for release, but we are tracking all of them on our GitLab repository.

  • MacOS versions earlier than 10.12 are no longer supported. Additionally, Bitcoin Cash Node does not yet change appearance when macOS "dark mode" is activated.

  • Windows users are recommended not to run multiple instances of bitcoin-qt or bitcoind on the same machine if the wallet feature is enabled. There is risk of data corruption if instances are configured to use the same wallet folder.

  • Some users have encountered unit tests failures when running in WSL environments (e.g. WSL/Ubuntu). At this time, WSL is not considered a supported environment for the software. This may change in future.

    The functional failure on WSL is tracked in Issue #33. It arises when competing node program instances are not prevented from opening the same wallet folder. Running multiple program instances with the same configured walletdir could potentially lead to data corruption. The failure has not been observed on other operating systems so far.

  • doc/ needs revision (Issue #65).

  • arc lint will advise that some src/ files are in need of reformatting or contain errors. - this is because code style checking is currently a work in progress while we adjust it to our own project requirements (see Issue #75). One file in doc also violates the lint tool (Issue #153), and a new script in test/benchmark/ likewise contains code that is flagged by the current linting configuration.

  • test_bitcoin can collide with temporary files if used by more than one user on the same system simultaneously. (Issue #43)

  • For users running from sources built with BerkeleyDB releases newer than the 5.3 which is used in this release, please take into consideration the database format compatibility issues described in Issue #34. When building from source it is recommended to use BerkeleyDB 5.3 as this avoids wallet database incompatibility issues with the official release.

  • There is a documentation build bug that causes some ordered lists on to be rendered incorrectly (Issue #141).

  • There is a report that the test_bitcoin-qt test executable fails on Linux Mint 20 (see Issue #144). This does not otherwise appear to impact the functioning of the BCHN software on that platform.

  • An 'autotools' build (the old build method) fails on OSX when using Clang. (Issue #129)

  • With a certain combination of build flags that included disabling the QR code library, a build failure was observed where an erroneous linking against the QR code library (not present) was attempted (Issue #138).

  • The 'autotools' build is known to require some workarounds in order to use the 'fuzzing' build feature (Issue #127).

  • Some functional tests are known to fail spuriously with varying probability. (see e.g. issue #148, and a fuller listing in #162).

  • Possible out-of-memory error when starting bitcoind with high excessiveblocksize value (Issue #156)

Changes since Bitcoin Cash Node 22.0.0

New documents

  • doc/ : an overview of the test networks supported by BCHN

Removed documents


Notable commits grouped by functionality

Network fixes

No changes.

Interfaces / RPC

  • 3379ccd1 Fix getblocktemplate sigop/blocksize limits to reflect -excessiveblocksize setting
  • 558a4a38 Add -expirerpc to list of intentionally undocumented CLI arguments
  • c21c8ee1 Implement Extversion
  • ac8192a8 Fix to EXTVERSION handshake causing peers to punish each other for misbehavior (simplified)
  • ad701aa8 [rpc] Override error messages in sendtoaddress
  • 1e90a52c Add 'finalization' & 'parking' debugging tracepoints
  • 5c62505c Add indexdir parameter to bitcoind
  • 44669a2e rpc: Add coin selection argument with fast option to sendtoaddress
  • 897b181b RPC: Add alias blockhash to getblockheader for backward compatibility
  • 1df9b1c8 RPC: Alias dummy for second arg to submitblock for compatibility

Peformance optimizations

  • 692fdfb4 [Net] Don't keep 3 copies of the NetMsgType strings in memory
  • f60a16c5 fix CTxMemPool::TrimToSize including too many things in pvNoSpendsRemaining
  • 84b36dd6 rpc: Change error checking of sendtoaddress to improve success path performance
  • 59a23ae3 [validation] Make CheckRegularTransaction about 2x-10x faster for typical tx by avoiding malloc
  • bf43658c Add option to reject and penalize headers deeper than finalized block


  • 1fc367e5 Fix Windows crash at startup introduced by MR !786

Code quality

  • 1de53291 SigHashType: document the footgun
  • 534469c0 [net] Follow-up to !622, reduce/remove some double-copies and other nits
  • a69b88a7 Restrict CBlockIndex to not allow copy, move, or assignment
  • e6748bc7 Remove unreferenced AVAPOLL and AVARESPONSE symbols from protocol.cpp
  • 42b1739e Make src/rpc/mining.cpp use config.GetMaxBlockSize() instead of DEFAULT_MAX_BLOCK_SIZE
  • fcb23ba7 Strong typing for UniValue, part 1: rename ObjectEntries, ArrayValues, write() (#51)
  • efeacd0c [Net] Make protocol string commands const-correct
  • 268537d1 Remove UniValue::__pushKV()
  • 63c3240b Improve UniValue array/object constructors/setters
  • 5abc0b8e Rename UniValue::find() to locate()
  • f0d956c1 Strong typing for UniValue, part 2: minor preparatory refactors (#51)
  • 027ecf82 [txmempool] Remove dangling/obsolete code in removeForBlock(...)
  • 56878c80 Introduce UniValue::at()
  • 198429f9 Made the CTransaction class no longer default constructible
  • 8dd5b076 Remove copy & assignment for CTranscaction for type safety
  • bbad18da [qa] Fix misleading comment in script_flags.h
  • 077d1d44 [trivial] Fixed a typo in a comment in the CTransaction class
  • 156de35e Introduce UniValue::size_type
  • be048a11 Strong typing for UniValue, part 3: Object and Array classes
  • 1cd875bf Improve UniValue::at() exception messages
  • 71f2d6b0 Upgrade UniValue::get_obj/get_array()
  • a657de33 Remove UniValue::takeArrayValues()
  • ea36c77d Remove UniValue::getArrayValues()
  • 3a524cf0 Remove UniValue::getObjectEntries()
  • 66ca616b Strong typing for UniValue, part 4: remove redundant object/array getter methods
  • bdbc0765 Fixed UniValue bug: don't take pointers to temporaries
  • 6785f662 Strong typing for UniValue, part 5: make copy-upcast constructors explicit
  • 2d30582f Remove declared but undefined function: fsbridge::freopen
  • e60b06a1 Prohibit implicit UniValue::VType to UniValue conversion
  • 53f5d4b4 Prohibit implicit UniValue copying
  • 3b5f03cf Prohibit implicit UniValue::Object copying
  • 0587870a Prohibit implicit UniValue::Array copying
  • ff0ea6b5 Replaced many instances of std::string pass-by-value with pass-by-ref
  • caf6845a Removed use of designated initializers from code: Not supported in C++-14
  • a9e3e4da Make more UniValue copy constructors explicit
  • 2313ef2b Make chainparamsseeds.h use numeric strings for human-readability
  • bfb3794c [wallet] Change return type of CreateTransaction
  • 2e5d7de3 [rpc] Replace error heuristics with rc check
  • 6eea1e10 Remove 'Optional'-related false positive uninitialized warnings on GCC
  • e3107d7c Fix GCC compile warning in seedspec6_tests.cpp related to missing braces
  • bf46211b [qa] Various cleanups in (linting and #173)

Documentation updates

  • 06557a8d mr -> mreq and mark commands and packages as such
  • c2d59dd3 [doc] Add 'bounty' label
  • 42706ea1 Update UniValue readme
  • 0fd21e4a [doc] Add test-networks document (to accompany introduction of testnet4/scalenet)
  • 24c868e8 [doc] Regenerate (update) the manpages and markdown docs for v22.1.0

Build / general

No changes.

Build / Linux

No changes.

Build / Windows

  • 7f87de89 Add NSIS related shortcut code changes

Build / MacOSX

No changes.

Tests / test framework

  • 229c11da [backport] tests: Make updatecoins_simulation_test deterministic
  • b970299e Functional test that getblocktemplate's size/sigop limits change with -excessiveblocksize
  • e56eaa03 Fix bchn-rpc-outdated-warnings functional test on slow PC
  • 610275b4 [qa] Improve sendtoaddress test coverage
  • db686fa9 Faster sendtoaddress RPC and spam generation/stress testing script
  • c8bd3ed9 Fix EXPECTED_VIOLATION_COUNT warning for check-functional


  • db686fa9 Faster sendtoaddress RPC and spam generation/stress testing script

Seeds / seeder software

  • c8c66af8 Fix seeder on chains without checkpoints

Maintainer tools

  • 4c2a598b This updates the static seed tools.
  • 1151bb26 Update static seed tooling and chainparams naming of static seed lists
  • 255e013a Detect -testnet4 and -scalenet from GetNetBoolArg call


  • fd8f0ff8 Make the default blocksize limit a consensus/chainparam value
  • d04560fc Update contrib/gitian-signing/keys.txt, contrib/gitian-signing/pubkeys.txt files
  • 29e5d7d3 [qa] Add imaginary_username gitian signing pubkey
  • 8ec7f4c6 [qa] Add freetrader launchpad signing pubkey
  • 174b0fd2 Add testnet4
  • fcd80dd1 Scalenet
  • cae98627 Remove seeders, they haven't been working for 8 months
  • e0904b56 Add new seeders
  • 16da9bf3 Add new mainnet seeder
  • 08e332d0 Scalenet and Testnet4 must use May 2020 HF height of 0


  • e2edfe59 [cleanup] Remove radix-tree

Continuous Integration (GitLab CI)

No changes.


  • 229c11da ABC: D6620: [backport] tests: Make updatecoins_simulation_test deterministic
  • 631697e3 ABC: D5689,D5619: [backport] Replace the test runner with a test wrapper ; Set environment variables when running tests with sanitizers