---
tags: eth2devs
description: Notes from the regular proof of stake [Eth2] implementers call
image: https://benjaminion.xyz/f/favicon-96x96.png
---

# PoS Implementers’ Call #88 - 2022-06-02
[Quick contemporaneous notes by Ben Edgington; fka "Eth2 Implementers' Call"]

Agenda: https://github.com/ethereum/pm/issues/536
Livestream: https://youtu.be/JeWOqtQS-KE

## Merge

### Ropsten deposit tracking issues

Is this isolated or a bigger problem?

Long block times (up to a minute) were causing inaccuracies in Eth1 voting in Lighthouse. Not an issue for mainnet unless block times get unusually long. LH is now switching over to Teku's algorithm which seems more robust.

Prysm suffered similar issues to LH and has now pushed a fix for it.

[Danny] There is certainly a desire to simplify this mechanism.

Meanwhile, no deposits have been processed onto the Ropsten beacon since genesis according to ropsten.beaconcha.in. Will investigate further after the call.

### sepolia beacon chain launch

Need to agree parameters and get Sepolia beacon chain launched. Can we do it within 2 weeks? No objections.

Launch, then Altair upgrade, but postpone Bellatrix upgrade for a while.

Will be permissioned, with ~2k validators.

Goerli or Sepolia to merge first? The last testnet will have the code closest to what will run The Merge itself - probably best to reserve that position for Goerli.

Pari to circulate dates and specs for Sepolia beacon chain next week.

### Ropsten TTD

When do we pick a number? Safest approach would be:

- Communicate privately with client teams to apply the TTD override to their clients.
- Add the TTD override on currently running clients after Bellatrix later tonight.
- Publish the TTD number in 24 hours.
- Target late next week for Merge, renting hash power if necessary.

Do clients need to bake in the new TTD value and make releases? Not urgent, but clients can add it in the next release cycle. Need to communicate to users that they should apply the TTD override manually. Good to get users to practise this. Reference for [how to override TTD](https://hackmd.io/ngKLqVvvTTGZLj1bGPuCoA).

### testing and general updates

Once Ropsten has merged, can we can deprecate Kiln? It costs money to keep it running. There are a number of large applications deployed on Kiln - we should keep it until the Merge. It _will_ be deprecated then.

Happy to deprecate Kintsugi now.

### Mainnet shadow fork 6

A couple of execution clients [struggled to produce blocks](https://notes.ethereum.org/PhbNw_cGSQ-VKqzGl4bPcg?view) with transactions. The issue of having zero lead time between prepare payload and get payload still exists on the consensus side - maybe only from Nimbus.

## Reorg incident review

Root cause was a change to the fork choice (proposer boost) that was deemed safe to roll out incrementally. This compounded with another spec bug (not running fork choice before proposing) to cause the reorg at the point when not quite a majority were running proposer boost.

Detailed [write up](https://barnabe.substack.com/p/pos-ethereum-reorg).

Lessons learned: need to analyse better how safe incremental roll out of fixes is; need to be more robust in our analysis against potential unknown issues arising; coordinate updates more tightly where needed.

## Research Updates

[Jacek] Nimbus team has started posting a bunch of PRs on light clients. Reflect discussions at Devconnect. Plan to split into smaller pieces, seek reviews and get it progressing.

Use case: if you are not running a validator but just need to read some Ethereum state you can use the light client protocol. It's a tiny application.

Please take a look at the PRs!

## Spec discussion and AOB

Teams, be sure to send someone to the ACD meetings. There are lots of decisions to be made.

* * *

# Chat highlights

From terence(prysmaticlabs) to Everyone 03:02 PM
: https://barnabe.substack.com/p/pos-ethereum-reorg?sd=fs&s=r

From danny to Everyone 03:02 PM
: https://github.com/ethereum/pm/issues/536

From Tim Beiko to Everyone 03:03 PM
: Might be worth touching on this too: https://twitter.com/calamenium/status/1532355860034371584
also there was a shadow fork yesterday!

From Tim Beiko to Everyone 03:08 PM
: looking at Ropsten etherscan, the difficulty is still going down each block so the cause is very likely just the disappearance of the high hash rate

From Tim Beiko to Everyone 03:20 PM
: +1 about training the override muscle :-)
https://hackmd.io/ngKLqVvvTTGZLj1bGPuCoA

From Lion dapplion to Everyone 03:25 PM
: The name of the Ropsten beacon chain is just "Ropsten beacon chain"?
For mainnet is easy because there's mainnet beacon chain, and mainnet "eth1". But for Goerli, there's two names: Prater and Goerli. Will some name take over? Or it will be a dual named merged testnet

From Tim Beiko to Everyone 03:26 PM
: does anyone have a quick link to the contact?
trying to find the address
0x6f22fFbC56eFF051aECF839396DD1eD9aD6BBA9D

From Fredrik to Everyone 03:26 PM
: https://ropsten.etherscan.io/address/0x6f22ffbc56eff051aecf839396dd1ed9ad6bba9d

From Tim Beiko to Everyone 03:27 PM
: 376 transactions to the contract
not sure if any are failed

From Fredrik to Everyone 03:27 PM
: last deposit ~3h ago

From Tim Beiko to Everyone 03:27 PM
: there are some few failed, but the bulk of them seem valid, so definitely 2-300 validators pending

From danny to Everyone 03:28 PM
: https://notes.ethereum.org/PhbNw_cGSQ-VKqzGl4bPcg?view

From Fredrik to Everyone 03:31 PM
: 336 validators pending: https://beaconchain.ropsten.ethdevops.io/validators/eth1deposits
here's one pending activation since 7 days (deposited by the "TTD miner"): https://beaconchain.ropsten.ethdevops.io/validator/0x96d8d5d511d6b1b3169369306baf2207983f3f54b8056e7882dd103d63583f44ddb836be26e22fb447da853c25e51432#deposits
(1 invalid)

From danny to Everyone 03:32 PM
: https://barnabe.substack.com/p/pos-ethereum-reorg?sd=fs&s=r

From Hsiao-Wei Wang to Everyone 03:34 PM
: > ropsten pending validator

: I guess beaconcha.in doensn't have Ropsten Eth1 chain node to provide the pending validator number on index