This week’s newsletter describes a recently fixed interoperability issue between different LN software and includes our regular sections with a list of new releases and release candidates plus notable changes to popular Bitcoin infrastructure software.

News

• ● LN interoperability: a recent change to the LN specification described in Newsletter #165 was implemented in different ways by different LN nodes, resulting in nodes running the latest version of LND being unable to open new channels with nodes running the latest versions of C-Lightning and Eclair. LND users are encouraged to upgrade to a bug fix release, 0.14.1 (described in the Releases and release candidates section below).

  A related discussion was started on the Lightning-Dev mailing list about improving interoperability testing. Christian Decker, who previously created and maintained the LN integration testing framework, said that he believes basic interoperability testing is “unlikely to catch any but the most egregious issues”. LN developers participating in the discussion noted that catching these sort of bugs is why every major implementation provides release candidates (RCs) and why expert users and administrators of production systems are encouraged to contribute to the testing of those RCs.

  For anyone interested in participating in such testing, the Optech newsletter lists RCs from four major LN implementations, plus various other Bitcoin software. The LND version under discussion was listed as an RC in Newsletters #174 and #175.

Releases and release candidates

New releases and release candidates for popular Bitcoin infrastructure projects. Please consider upgrading to new releases or helping to test release candidates.

• ● LND 0.14.1-beta is a maintenance release that fixes the issue described in more detail both in the News section above and in the description of LND #6026 in the Notable changes section below.

Notable code and documentation changes

Notable changes this week in Bitcoin Core, C-Lightning, Eclair, LND, Rust-Lightning, libsecp256k1, Hardware Wallet Interface (HWI), Rust Bitcoin, BTCPay Server, BDK, Bitcoin Improvement Proposals (BIPs), and Lightning BOLTs.

• ● Bitcoin Core #16807 updates address validation to return the indices of likely typos in bech32 and bech32m addresses using the mechanism described in Newsletter #41. The typos will be correctly identified if no more than two substitution errors were made. The pull request also improves test coverage, adds more documentation to the address validation code, and improves error messages when decoding fails, especially to distinguish use of bech32 and bech32m.

• ● Bitcoin Core #22364 adds support for creating descriptors for taproot. This allows wallet users to generate and use P2TR addresses by creating a default bech32m descriptor with their wallet instead of importing one.

• ● LND #6026 fixes an issue with the implementation of BOLTs #880 explicit channel type negotiation (see Newsletter #165). A proposed change to the LN specification would allow LND to eventually implement strict explicit negotiation.

• ● Rust-Lightning #1176 adds initial support for anchor outputs-style fee bumping. As of this merge, support for anchor outputs is implemented in all four LN implementations we cover.

• ● HWI #475 adds support for the Blockstream Jade hardware signer and tests using the QEMU emulator.