Meetings: add 2018-07-19

Author: harding

_includes/references.md

@@ -33,6 +33,7 @@
 [Joshua Simmons]: https://github.com/kadoban
 [Karel Bilek]: https://github.com/karel-3d
 [Karl-Johan Alm]: https://github.com/kallewoof
+[Lucas Betschart]: https://github.com/lclc
 [Luke Dashjr]: https://github.com/luke-jr
 [Marco Falke]: https://github.com/MarcoFalke
 [Mark Erhardt]: https://github.com/Xekyo
@@ -130,3 +131,10 @@
 [recent-contributors]: https://github.com/bitcoin/bitcoin/graphs/contributors?from=2017-03-01
 
 [website-issues]: https://github.com/bitcoin-core/bitcoincore.org/issues
+
+{% comment %}
+<!--REQUIRES PERIODIC UPDATE: update rpc_version below to latest
+version of this site's RPC docs-->
+{% endcomment %}
+{% assign rpc_version = "0.16.1" %}
+[rpc fundrawtransaction]: /en/doc/{{rpc_version}}/rpc/rawtransactions/fundrawtransaction/

_posts/en/meetings/2018-07-19-meeting.md

@@ -0,0 +1,304 @@
+---
+title: IRC meeting summary for 2018-07-19
+lang: en
+permalink: /en/meetings/2018/07/19/
+name: 2018-07-19-meeting
+layout: page
+type: meetings
+version: 1
+---
+{% include toc.html %}
+{% include references.md %}
+
+- View this week's log on [BotBot.me][bbm log] or [MeetBot][mb log]
+- [Meeting minutes by MeetBot][mb minutes]
+
+---
+
+Topics discussed during this weekly meeting included pull requests that
+need to be reviewed before Monday's feature freeze for Bitcoin Core
+0.17, whether or not Bitcoin Core's algorithm for selection of which
+inputs (coins) to spend should be made available as an RPC, a new way of
+describing which outputs the wallet should monitor and an implementation
+of this method for the new `scantxoutset` RPC, whether Pieter Wuille's
+bitcoin-seeder program should become part of the Bitcoin Core GitHub
+organization, whether the Bitcoin Core project should stop publishing
+release notes and binaries to Bitcoin.org, and information about the
+next CoreDev Tech meeting.
+
+Prior to the start of discussion, Wladimir van der Laan mentioned that
+the executables for Bitcoin Core 0.16.2 Release Candidate (RC) 2 are
+[available for testers][0.16.2rc2 bin].
+
+## High priority for review
+
+**Background:** each meeting, Bitcoin Core developers discuss which Pull
+Requests (PRs) the meeting participants think most need review in the
+upcoming week.  Some of these PRs are related to code that contributors
+especially want to see in the next release; others are PRs that are
+blocking further work or which require significant maintenance (rebasing)
+to keep in a pending state.  Any capable reviewers are encouraged to
+visit the project's list of [current high-priority
+PRs][].
+
+A special focus of this meeting was PRs that needed to be merged in the
+next few days if their features are to be included in upcoming version
+Bitcoin Core 0.17, so reviewers are also encouraged to check the list of
+PRs in the [0.17 milestone][].
+
+**Discussion ([log][log hipri]):** the following PRs were discussed:
+
+- [#9662][] - Add create wallet "disableprivatekeys" option: a sane mode
+  for watchonly-wallets.  Requested by Jonas Schnelli; Wladimir van der
+  Laan said it could probably be merged soon.
+
+- [#9502][] - [Qt] Add option to pause/resume block downloads.
+  Requested by Schnelli.
+
+- [#13697][] - Support output descriptors in scantxoutset.  Requested by
+  Pieter Wuille with support from Schnelli.  Discussed in more detail
+  [later](#osd) in the meeting.
+  
+  
+- [#13666][] - Always create signatures with Low R values.  Requested by
+  Wuille.
+
+- [#13426][] - [Bugfix] Add u8path and u8string to fix encoding issue
+  for Windows.  Requested by Chun Kuan Lee.
+
+- [#13712][] - Wallet: Fix non-determinism in ParseHDKeypath; avoid
+  using an uninitialized variable in path calculation.  Requested by
+  Andrew Chow.
+
+- [#8469][] - [POC] Introducing property-based testing to Core.
+  Requested to be removed from the 0.17 list by Schnelli, as it's not
+  ready.
+
+- [#13617][] - Require MacOS 10.10+.  Initially requested for removal
+  from the list, but added back after a comment by Cory Fields.
+
+**Conclusion:** there were over a dozen PRs tagged for 0.17 by the end
+of this segment of the meeting for a review deadline of Monday.
+
+## Exposing coin selection on RPC
+
+**Background:** Coin selection is the name used for how a wallet chooses
+which of a user's bitcoins to spend in a particular transaction.  The
+selected *Unspent Transaction Outputs (UTXOs)*, often simply called
+*coins,* become *inputs* in the transaction.  Developers have spent many
+hours in the past year improving Bitcoin Core's coin selection to be
+able to sometimes improve privacy and lower transaction sizes (thus
+reducing fees) for users of Bitcoin Core's built-in wallet, with more
+improvements on the way.
+
+**Discussion ([log][log rpc coin selection]):** Andrew Chow requested
+the topic and introduced it: "This came up in a discussion with some
+companies about coin selection.  Basically, some are interested in using
+Core's coin selection (or someone else's) instead of having to
+implement/roll their own.  Currently if they wanted to use Core's coin
+selection, the UTXOs need to be in the wallet---i.e., the addresses and
+possibly keys need to be in the wallet."
+
+Wladimir van der Laan and Gregory Maxwell suggested that they could use the
+[`fundrawtransaction`][rpc fundrawtransaction] RPC to use Bitcoin Core's
+coin selection.  Jonas Schnelli added, "using private key disabled
+dynamic wallet in conjunction with fundraw seems very efficient,"
+referring in part to PR [#9662][].
+
+Chow said, "that is not ideal for them" and Pieter Wuille followed up
+with, "they'd don't want to use the wallet; they just want to be able to
+run coin selection."
+
+Several meeting participants suggested it could be done as a library,
+but Maxwell argued against doing it within the project as either an RPC
+or a library: "I am doubtful that it is worth our effort in maintaining
+a stable interface for such a thing.  E.g.  [Kalle Alm]'s recent
+[grouping PR][#12257] would've obliterated the interface for coin
+selection [...] Pressure to maintain a stable interface to [coin
+selection] would be harmful to the project.  [...] I don't want to hear
+'we can't implement privacy feature X because it'll break [the coin
+selection] interface'."
+
+Wladimir van der Laan said, "I think this is not a concern for our
+project.  Some other people want a coin selection algorithm for their
+own purposes.  [That's] fine, they can make a library out of it
+themselves, the code is open source."  Maxwell suggested, "Perhaps they
+should contribute to making the wallet code better so they don't have
+to write their own (smiley face with tongue sticking out)."
+
+**Conclusion:** although the idea of an RPC method was generally
+opposed, Wuille did suggest a path forward: "I think the first step for
+this is something we're doing anyway: making the code itself more
+encapsulated.  Perhaps once the code is sufficiently encapsulated,
+someone else can librarify that and maintain it."
+
+## <!----> #13697 which changes the API for scantxoutset {#osd}
+
+**Background:** recently-merged PR [#12196][] adds a `scantxoutset` RPC
+that allows the user to search the set of currently-spendable bitcoins
+(UTXO set) for any outputs that correspond to one or more specified
+addresses, public keys, private keys, or set of HD keys.  As discussed
+in the [June 28th][meet osd] meeting, Pieter Wuille is working on a [new
+way][osd gist] to specify what outputs (scriptPubKeys) a wallet should
+look for, called Output Script Descriptors, and he has PR [#13697][] open
+to add support for that to `scantxoutset` instead of the current ways
+keys and scripts are described to the wallet.
+
+**Discussion ([log][log scantxoutset api]):** Wuille requested and
+introduced the topic, "first of all, this is part a bigger effort to
+combine keys and scripts and [HD wallet] chains into one concept.
+There's a mini language to specify (sets of) scriptPubKeys, so I'd very
+much first want to hear comments on that language.  The other question
+is [whether] `scantxoutset` [is] experimental or not, and [is it so]
+with descriptor support in 0.17 or not?"
+
+Wladimir van der Laan and Jonas Schnelli both said they liked the idea
+of output script descriptors, and they also both supported marking
+`scantxoutset` as experimental for the 0.17 release, which will allow the
+project to freely change its API for subsequent releases and make it
+easy to incorporate feedback from users of the new RPC and new output
+script descriptors language.
+
+Luke Dashjr asked, "Should [output script descriptors] be a BIP?  Seems
+potentially useful outside Core."  Wuille replied, "potentially yes, but
+not in the first instance.  I expect that this will evolve rather
+quickly."
+
+**Conclusion:** No objections were raised to the idea of marking
+`scantxoutset` experimental for the 0.17 release, or to using output
+script descriptors if [#13697][] passes review.
+
+## Bitcoin-seeder under bitcoin-core GitHub organization
+
+**Background:** although Bitcoin uses a peer-to-peer protocol, nodes
+started for the first time don't know the IP addresses of any peers to
+connect to (except for some fallback addresses for last-ditch use), so
+they request a list of IP address for recently-active notes from a
+program called a *Bitcoin seeder.*  The node then connects to those
+peers and those peers can tell the new node about other peers, so all
+future connections can often be made completely decentralized---but a
+node can use the seeder again if decentralized peer finding isn't
+working for it.
+
+There are several seeder programs written by different authors.  One of
+them is maintained by Pieter Wuille and is simply called `bitcoin-seeder`. 
+
+**Discussion ([log][log seeder]):** Lucas Betschart requested and
+introduced the topic: "I thought because there are a few open issues and
+simple PRs for bitcoin-seeder [that] it might make sense that several
+Bitcoin maintainers have merge rights."
+
+Wuille replied, "No problem as far as I'm concerned, but I'm not sure
+it's the right message."  Luke Dashjr echoed that sentiment.
+
+**Conclusion:** Sjors Provoost suggested, "another approach could be for
+[Wuille] to give more people access to that repository?"  Wuille replied,
+"I'm fine with that!"  Betschart said, "That's also fine with me."
+
+## Moving away from Bitcoin.org
+
+**Background:** Since the 2009 release of the original Bitcoin software,
+Bitcoin Core resources were traditionally hosted on Bitcoin.org.  But
+over time, this was augmented with additional resources about the
+increasingly diverse Bitcoin network, so (in December 2015) Bitcoin Core
+began using its own domain---initially just to host its resources but
+now also to host its software releases.  However, release announcements
+and software continue to be mirrored to Bitcoin.org.
+
+**Discussion:** please see the [log][log bco].  Note some discussion
+also occurred [after the meeting][post-meeting bco].
+
+[post-meeting bco]: https://botbot.me/freenode/bitcoin-core-dev/msg/102258762/
+
+**Conclusion:** no explicit conclusion.  Post-meeting discussion seemed
+to indicate no significant changes to the current process.
+
+## Next CoreDev tech meeting
+
+**Background:** periodically, some members of the Bitcoin Core team hold
+an invitation-only event mainly for contributors to Bitcoin Core to
+allow everyone to review and discuss various projects in person.  For
+more information, see the [CoreDev.Tech][] website.
+
+**Discussion ([log][log coredev meet]):** Steve Lee requested and
+introduced the topic, "I've volunteered to organize the next Core Dev
+Tech meetup.  The current thinking is to have it in Tokyo in October
+after Scaling Bitcoin, October 8-10, and to organize it in a similar
+fashion as the last one in NYC."
+
+Several people thanked Lee.
+
+**Conclusion:** Lee said, "I plan to send out a survey to collect some
+feedback.  If anyone has specific ideas or suggestions, please feel free
+to contact me."
+
+## Humor
+
+{% highlight text %}
+          <sipa> what about #13666 ?
+<provoostenator> What's in a number?
+          <sipa> 13 and 666, can't beat those odds
+        <wumpus> niice
+      <achow101> it was completely planned, obviously
+          <sipa> in some timezones it was also opened on
+                 friday the 13th
+                 oh, no
+ <jonasschnelli> I hope no black cat was sitting on the
+                 keyboard during coding
+{% endhighlight %}
+
+
+## Participants
+
+| IRC nick        | Name/Nym                  |
+|-----------------|---------------------------|
+| wumpus          | [Wladimir van der Laan][] |
+| sipa            | [Pieter Wuille][]         |
+| jonasschnelli   | [Jonas Schnelli][]        |
+| achow101        | [Andrew Chow][]           |
+| luke-jr         | [Luke Dashjr][]           |
+| gmaxwell        | [Gregory Maxwell][]       |
+| moneyball       | [Steve Lee][]             |
+| provoostenator  | [Sjors Provoost][]        |
+| jnewbery        | [John Newbery][]          |
+| cfields         | [Cory Fields][]           |
+| lclc            | [Lucas Betschart][]       |
+| ken2812221      | [Chun Kuan Lee][]         |
+| kanzure         | [Bryan Bishop][]          |
+
+## Disclaimer
+
+This summary was compiled without input from any of the participants in
+the discussion, so any errors are the fault of the summary author and
+not the discussion participants.  In particular, quotes taken from the
+discussion had their capitalization, punctuation, and spelling modified
+to produce consistent sentences.  Bracketed words and fragments, as well
+as background narratives and exposition, were added by the author of
+this summary and may have accidentally changed the meaning of some
+sentences.  If you believe any quote was taken out of context, please
+[open an issue](https://github.com/bitcoin-core/bitcoincore.org/issues/new)
+and we will correct the mistake.
+
+[bbm log]: https://botbot.me/freenode/bitcoin-core-dev/msg/102255898/
+[mb minutes]: http://www.erisian.com.au/meetbot/bitcoin-core-dev/2018/bitcoin-core-dev.2018-07-19-19.02.html
+
+[current high-priority PRs]: https://github.com/bitcoin/bitcoin/projects/8
+
+{% assign log = "http://www.erisian.com.au/meetbot/bitcoin-core-dev/2018/bitcoin-core-dev.2018-07-19-19.02.log.html" %}
+[mb log]: {{log}}
+[log hipri]: {{log}}#l-13
+[log rpc coin selection]: {{log}}#l-77
+[log scantxoutset api]: {{log}}#l-173
+[log seeder]: {{log}}#l-207
+[log bco]: {{log}}#l-231
+[log coredev meet]: {{log}}#l-279
+
+[meet osd]: /en/meetings/2018/06/28/#output-script-descriptors
+[osd gist]: https://gist.github.com/sipa/e3d23d498c430bb601c5bca83523fa82
+[coredev.tech]: https://coredev.tech/
+
+[0.16.2rc2 bin]: https://bitcoincore.org/bin/bitcoin-core-0.16.2/test.rc2/
+[0.17 milestone]: https://github.com/bitcoin/bitcoin/milestone/33
+
+
+{% include link-to-issues.md issues="9662,9502,13697,13666,13426,13712,8469,13617,12196,12257" %}