This week in Bitcoin Core

Bitcoin Core contributor kevkevin covers some of the latest updates...

Hello 👋 folks, I’m kevkevin. I’m an open-source developer and reporter for Insider Edition. Last week, I reviewed several pull requests from the Bitcoin Core repo. Here’s what I found notable.

Merged PR’s

Every week, several changes are officially added to Bitcoin Core. This week, 38 changes were merged. Here are some I thought were interesting from this week.

• wallet: Be able to receive and spend inputs involving MuSig2 aggregate keys by achow101

  This PR implements MuSig2 signing so that the wallet can receive and spend from imported musig(0 descriptors. If you need some background info on what MuSig2 is, you can refer to this Bitcoin Optech post.
  
  This is a fairly large/important change, as it enables the use of aggregate public keys and signatures using the Schnorr signature algorithm. This provides many benefits, but you can read more about MuSig2 and its benefits in the above post. Or you can read this post by Bitcoin Dev project explaining MuSig2 simply.

• cluster mempool: control/optimize TxGraph memory usage by sipa

  The main goal of this PR is to optimize the memory usage of TxGraph. TxGraph is an important part of cluster mempool as it handles the linearization of the clusters. In this change, Sipa exposes the GetMainMemoryUsage function to compute the approximate memory usage of TxGraph.

  This change allowed for optimizations to be done to TxGraph and is a big win for cluster mempool, as it will make it easier to run on smaller systems like a Raspberry Pi.

• coins: fix cachedCoinsUsage accounting in CCoinsViewCache by l0rinc

This PR fixes cachedCoinsUsage accounting bugs in CCoinsViewCache that caused UBSan unsigned-integer-overflow violations during testing. The issues stemmed from incorrect decrement timing in AddCoin(), unconditional reset in Flush() on failure, and incorrect increment in EmplaceCoinInternalDANGER() when insertion fails.

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Open PR’s

There are always changes being updated and reviewed in real-time. Here are some notable PR’s that are still up and looking for reviews.

• Cluster mempool by sdaftuar

  This is the same cluster mempool PR, but it was reopened in a new PR because there were so many comments on the previous one, making it difficult to review, as it would take a long time to open the GitHub page.
  
  Nonetheless, this is a good opportunity to give this PR a review.

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IRC meeting notes

Every week on Thursday, there is an IRC meeting. Here are some short notes from that meeting.

• Kernel WG Update (TheCharlatan)

  • TheCharlatan: Got some first ACKs on #30595 this week, looking for some more eyeballs.

• Cluster Mempool WG Update (sdaftuar, sipa)

  • sipa: #33157 got merged, thanks for all the reviews! that’s pretty much all of txgraph in, apart from a few small things which won’t block anything. the focus is now #33629, which is a rebased, and reduced version of the older 28676 cluster mempool PR. follow-ups have been split off in #33591.

  • There is some additional conversation on this topic which can be read in the full meeting in minutes below

• MuSig2 WG Update (achow101)

  • sipa: it’s merged!?

  • achow101: #29675 was merged!

  • sipa: woohoo

  • glozow: musig to my ears!

  • achow101: fjahr opened a followups pr: #33636

  • achow101: but I think this working group is done :D

For the full log, check the meeting in minutes

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Releases

• Bitcoin Core 28.3 Release Candidate 2 Available

• Bitcoin Core v29.2 Released

• Bitcoin Core v30.0 Released

• Bitcoin Knots 29.2.knots20251010 released

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Thank you for reading. Be sure to tune in again next week for your updates on Bitcoin Core!