Checkpoint - March 2025 | Ethereum Foundation Blog

Ethereum’s weekly All Core Developer calls are a lot to keep up with, so this "Checkpoint" series aims for brief high-level updates with a target cadence of every 4-5 calls, depending on what’s happening in core development. See the initial update here. All subsequent updates will be hosted here on the Ethereum Foundation blog.

The past month of calls have been focused on Pectra’s testnet upgrades in anticipation of the Pectra mainnet fork with development of the following fork, Fusaka, pushing forward in parallel.

Pectra

Both major testnets, Holešky and Sepolia, underwent the Pectra fork and both saw configuration issues that required immediate attention. The issues on both testnets were specific to their configuration as testnets, and would not have been issues on mainnet, i.e. the fork code and configuration was built with mainnet in mind and missed some configuration tweaks that were necessary for the fork to go smoothly on testnets. A new testnet, Hoodi, was launched to test Pectra features and the Pectra Audit Competition closes on March 27th.

Holešky

The testnet has recovered and the post-mortem can be found here. Holešky is a permissionless testnet with an open validator set and therefore took a lot of coordination among independent operators to come to finalization after a majority of the network forked to a non-canonical chain. Though network finality recovered, it resulted in so many validator exits that the exit queue is a year long and many Pectra features that require exits need a new home for testing.

To that end, a new long-lived testnet, Hoodi, was launched and will undergo the Pectra fork on March 26th. Liquid staking protocols and other validator operators can use Hoodi for Pectra feature testing.

Sepolia

Sepolia’s Pectra incident was quickly resolved and the post-mortem can be found here. The configuration issue on Sepolia was less severe, did not result in a majority fork as Holešky did, and due to Sepolia’s permissioned validator set, was much quicker to coordinate a fix.

Timeline

The most recent call discussed when core devs thought it would be prudent to set a date for mainnet activation of Pectra. Devs agreed that conditions to set a date included a successful Hoodi fork with some time to monitor and liquid staking protocols successfully testing Pectra features on the new testnet.

Provided there are no unexpected issues, we can expect a mainnet fork epoch to be chosen in the next 2-3 ACD meetings.

History expiry

Because not all consensus clients support the new deposit snapshot format yet and there's still a risk that these snapshots might not be shared reliably over the network, the "drop day" for history expiry will be delayed until Pectra ships on Mainnet, since Pectra includes EIP-6110, an upgrade which removes the dependency on pre-merge history. May 1st will now be used to test history expiry on Sepolia.

Fusaka

While core devs are primarily focused on shipping Pectra, devnet testing is progressing for the two major features scheduled for inclusion (”SFI”) in Fusaka: PeerDAS and EOF. Many other EIPs have been proposed for inclusion (”PFI”) but there’s a strong desire among core developers to keep the fork as small as possible in order to ship PeerDAS as soon as possible, so all EIPs PFI’d will be facing an uphill battle to move to SFI status.

There’s some growing pushback against the complexity that EOF introduces and alternative proposals, with unwavering support on the other side and no consensus for removal as of now.

Timeline

Fusaka deadlines are as follows:

March 24: deadline for EIPs to be Proposed for Inclusion (”PFI”)
March 31: deadline for client teams to share their preferences about scope, including which EIPs they think should be Declined for Inclusion (”DFI”)
April 10: Fusaka scope frozen

In February's ACD wrap-up, aka "Checkpoint", the overwhelming sentiment on where to prioritize focus was on scaling and cadence acceleration. Indeed, the pressing need for PeerDAS, gas limit increases, and more blobs has taken a front row seat in immediate concerns. But the stress of two testnets in a row needing recovery has shifted sentiment slightly back toward a desire to ship ‘quickly but with max care’.

There has also been some preliminary conversation around protocol hardening with more robust security, testing procedures, and standardized configurations. The next few months will likely see the introduction of new processes to reduce the risk of complications during a mainnet upgrade.