Ethereum Protocol Fellowship (EPF) Cohort 7 — Applications open until May 13

FOCIL Breakout #031

2026-03-24 Agenda: #1978 canonical JSON

Transcript

00:11:23
Jihoon:Hello everyone, welcome to FOCIL Breakout 31. Today we can share
00:11:30
Jihoon:Development updates, backup days, and then testing.
00:11:36
Jihoon:Right, so, let's start with development updates.
00:11:41
Jihoon:I know CL teams are busy with ePBS, so maybe we can start with EL teams?
00:11:50
Justin Florentine (Besu):Hey, yeah, so on the basis side, we haven't done a ton since last call. We still have a PR out there, it's still in review right now. No surprises to report from the spec?
00:12:04
Justin Florentine (Besu):So, you know, it is basically mostly just engine API implementation and some building stuff, so it's going well.
00:12:13
Justin Florentine (Besu):It's just not, not a super high priority. Most of the team is focused on, optimizations and Glamsterdam stuff at the moment.
00:12:24
Jihoon:Cool, do you have any, like, rough timeline?
00:12:33
Justin Florentine (Besu):No, not at the time, at the moment, we don't really have a rough timeline. Certainly, Hegota wouldn't be a challenge.
00:12:43
Justin Florentine (Besu):you know, with a typical DevNet rollout for whenever Hegota hits, we don't see a challenge, but I would need a little bit of time to consult with Fabio. I'm actually going to be going on holiday shortly, and so I wouldn't want to try to commit to any usable builds.
00:13:07
Jihoon:yeah, I just wanted to ask you about, like.
00:13:13
Jihoon:What we can expect in the interop.
00:13:18
Justin Florentine (Besu):Interop. Okay, so I won't be attending Interop… Alright.
00:13:25
Justin Florentine (Besu):I mean, I would imagine we would have something build-ready for… for Interop?
00:13:38
Justin Florentine (Besu):Yeah, I mean, I mean… Probably? I don't see any reason why not, I guess.
00:13:46
Justin Florentine (Besu):the, the, you know, the testnets and the kurtosis stacks that, we would use to validate for that, once we get one of those, we can give a better, better answer. Or, like, once we get that set up, rather, we can give a clearer answer on that.
00:14:04
Justin Florentine (Besu):But A month. It's about a month out.
00:14:07
Justin Florentine (Besu):Right? So 4 weeks… 4 weeks from now for being able to join a DevNet, I think is pretty reasonable.
00:14:15
Justin Florentine (Besu):I don't really see a problem with that.
00:14:21
Jihoon:Nico, do you have any updates for Lodestar?
00:14:26
nflaig:No, sorry. Right now, no real updates.
00:14:30
nflaig:I saw your comment on the Beacon API, but I also think it's just minor, like updating the containers.
00:14:40
nflaig:Yeah, I hope we have something for the indoor. If not, I think we can hack something together in, like, a few hours.
00:14:48
nflaig:I think it's pretty simple, to be honest.
00:14:52
Jihoon:Yeah, no worries. But was my comment on Beacon API?
00:15:00
nflaig:I think this is currently based on Fulu,
00:15:05
nflaig:But I don't see major changes to rebase it on Hegota.
00:15:11
Jihoon:Right, yeah, yeah, yeah, yeah. I was updating all specs, so I was just, I just wanted to ask if there is anything that we have to make change on Beacon API, so… yeah.
00:15:27
nflaig:Probably do this, once we update our implementation, and then we can use that as reference.
00:15:36
Jihoon:Gotcha. And if you have a time, then,
00:15:42
Jihoon:It'll be appreciated if you could review the spec yourself.
00:15:48
Jihoon:It is currently not reviewed at the moment.
00:15:52
Jihoon:But it will get reviewed over time, but still, like.
00:15:55
Jihoon:It's nice to have more eyes on the spec, so…
00:16:03
nflaig:Yeah, I think once we have our implementation, it's easier to give feedback there.
00:16:12
nflaig:But yeah, I can see if I find time to look at it.
00:16:20
Jihoon:Speaking of which, for spec updates,
00:16:25
Jihoon:I'm working on rebasing all specs on top of Hegota.
00:16:29
Jihoon:Avery-based execution spec and engine API spec.
00:16:34
Jihoon:I guess you guys already have a link, but… It's a lead.
00:16:42
Jihoon:If anyone is interested. So they are currently on top of Glamsterdam.
00:16:48
Jihoon:And I can update it from time to time, just in case Glamsterdam changes.
00:16:54
Jihoon:CL spec is already on top of Hegota, but…
00:16:58
Jihoon:There will be some changes regarding deadline.
00:17:02
Jihoon:The gist of it is… so currently we have two deadlines. IL submission deadline at 9 seconds into the slot.
00:17:12
Jihoon:And proposals cut off at 11 seconds into the slot.
00:17:17
Jihoon:And I think we should add another deadline for a tester's cutoff at, let's say, 12 seconds into the slot.
00:17:27
Jihoon:This was found by Mikhail around 9 months ago.
00:17:31
Jihoon:well, there is another deadline, which is 8 seconds into the slot, but as Nico pointed out nearly a year ago, I think this should be removed. This is just…
00:17:43
Jihoon:Implementation-dependent example.
00:17:46
Jihoon:So the reason why we need this new 12-second deadline is…
00:17:52
Jihoon:to prevent split view among the testers, let's say there is an inclusion list, that…
00:17:59
Jihoon:the block fails to satisfy, and that IR committee member actually equivocates.
00:18:07
Jihoon:which, in turn, should make that block become canonical, but let's say that that equivocation happens at 2 seconds into the swap. So.
00:18:19
Jihoon:Then, attester who saw the block before 2 seconds will vote against it, while a tester who saw it after will vote for it. So if
00:18:29
Jihoon:Half of a tester vote for it, half of a tester vote against it, because they haven't seen that equivocating IL committee member, we're gonna have a split view.
00:18:40
Jihoon:It's… this is still work in progress, and I think I can continue working on it.
00:18:45
Jihoon:After 8cc… And… Once it's done, I will also update the EIP,
00:18:54
Jihoon:So, yeah, that's for the spec updates.
00:18:58
Jihoon:Before we jump to… testing updates? Do we have any questions or comments?
00:19:14
Jihoon:Otherwise, we can just move on.
00:19:18
Jihoon:So for testing, I guess you guys already know, but there are…
00:19:23
Jihoon:all types of tests that we can do on the CL. Reference tests, buzzing, deafness, and compliance tests. Among these, we can focus on
00:19:33
Jihoon:Reference test for a while, and extend testing over time.
00:19:38
Jihoon:On the EL side, we will be working on a steel team.
00:19:43
Jihoon:We don't have anyone from testing team today, but this is… Asia Tracker… for AL testing.
00:19:57
Jihoon:the idea… we had a call with testing team the other day, and the idea is to update the testing infra in the tests to support inclusion list, and then start from there.
00:20:10
Jihoon:Besides that, besides specs, updates.
00:20:14
Jihoon:Nothing special updates we have today, but I expect we can make some progress after ECC.
00:20:21
Jihoon:And that's all for testing updates.
00:20:26
Jihoon:Yeah, so, before we wrap up this call.
00:20:29
Jihoon:Does anyone have any comments or questions?
00:20:44
Jihoon:And thank you for your comments.
00:20:51
Jihoon:I wanted to find that comment, but I guess it's not on Discord, I think it's on some PR, but yeah. I've been thinking about it from time to time, and now it's time to update it, so yeah.
00:21:08
Jihoon:Alright, I think that's it for today. If anyone here goes ECC, we can see each other there.
00:21:16
Jihoon:Otherwise, let's catch up in 2 weeks. Thank you, guys!

Chat Logs

00:16:42
Jihoon:EEST: https://github.com/ethereum/execution-specs/pull/1928 Engine APIs spec: https://github.com/ethereum/execution-apis/pull/609
00:19:54
Jihoon:https://github.com/ethereum/execution-specs/issues/1900
00:20:41
nflaig:great work on the spec side!

Summary

9 highlights · 2 action itemsExperimental

development progress

  • Besu: PR under review; Hegotá timeline feasible, prioritizing Glamsterdam optimizations00:12:03
  • Besu targeting build-ready status for Interop (~4 weeks out)00:13:43
  • Lodestar: Implementation simple, can hack together in hours if needed00:14:30

spec updates

  • All specs rebasing to Hegotá: execution-specs, engine-apis completed; CL spec updates pending00:16:29
  • New 12-second attester cutoff deadline needed to prevent split view during equivocations00:17:01
  • Split view issue: attesters seeing IL equivocation at different times vote inconsistently00:18:19
  • 8-second deadline to be removed as implementation-dependent example00:19:23

testing updates

  • CL: Focus on reference tests initially, expand to fuzzing/devnets later00:19:33
  • EL: Updating test infra to support inclusion lists with testing team00:19:42

Action Items

  • All teams: Review rebased execution-specs PR #1928 and engine-apis PR #60900:16:32
  • Jihoon: Finalize attester cutoff deadline spec changes post-ECC00:17:51

Targets

  • Post-ECC - Resume spec and testing progress00:20:51
  • April 7, 2026 - Next FOCIL Breakout #3200:21:15