Bitcoin Knots 29.4.1 rc4

Bitcoin Knots v29.4.1.knots20260508rc4, packaged for StartOS.

What rc4 changes

rc4 schedules the BLAKE2b proof of work change on mainnet at height 961640, which rc3 did not, and moves the testnet4 height from 150027 to 150308.

Mainnet is already past 961640 and testnet4 is past 150308, so on either network this node follows the BLAKE2b chain from the activation height and reorganises away from the chain it is currently on. Blocks below the activation height stay valid; everything above is rebuilt. Anything indexing the node, an Electrum server in particular, will need to rebuild its own index afterwards.

This build does not force testnet4

The upstream release candidate packages pin -chain=testnet4 in the daemon arguments, so a node that took one of those updates was moved onto testnet4 regardless of its own settings, and a node that was on mainnet stopped being on mainnet without anything in its configuration changing.

That pin is removed here. The chain comes from bitcoin.conf and defaults to mainnet, so a node that was on mainnet before those updates returns to it. Existing chain data for both networks is left alone, mainnet at the top level of the volume and testnet4 in its own subdirectory, so returning to a network you already synced does not resync it.

The same assumption was in the configuration file model, which wrote every setting into a [testnet4] section. A network section only applies on that network, so on mainnet none of the settings took effect, blake2b_headline included, and since that value is mandatory the node refused to start with no way to correct it from the interface. Settings are now written at the top level. Reading still accepts the old section, so existing configuration is preserved.

A configuration file written by an earlier release candidate keeps its [testnet4] header until the configuration is saved again, which rewrites it flat.

Scope

Universal package covering x86_64, aarch64 and riscv64. Built from rc4 at 5ffd699, based on upstream's v29.4.1_3-knots with the release candidate bumped, the testnet4 network pin removed, and the configuration file model corrected.

Verifying this download

gpg --import privkeyio-signing-key.asc
gpg --verify bitcoind_x86_64.s9pk.sha256.asc bitcoind_x86_64.s9pk.sha256
sha256sum -c bitcoind_x86_64.s9pk.sha256

Signed by Kyle Santiago kyle@privkey.io, key A47D99B6DB0D715D40C59A2023AE8A8EA7E24E38.