ACDC #186 · Sepolia fork Scheduled for October 6
AllCoreDevs - Consensus #186 · 2026-09-03
The Glamsterdam upgrade gets its first public testnet date
The Glamsterdam fork date on the Sepolia testnet was set for October 6, 2026, and the Hoodi date was pushed to the next call. A bug fix for state gas EIP-8037 was also confirmed with the agreement of all execution layer clients.
Why it matters
This is a signal that the Glamsterdam hard fork is moving past developer-only networks into the public testnet stage. However, the 1,000-node DevNet is not yet stable, so the date could be adjusted again if client problems continue.
Decisions
- EIP-8037 fix: The fix for the cross-frame state gas bug in EIP-8037, which will go into Glamsterdam, was approved, and all EL clients have implemented it and will deploy it to DevNet 8. This means a defect in an already included feature is fixed before the fork.
- Parent hash check: A consensus spec fix adds a check that a block hash is not equal to its parent hash, and every client will implement it. It guards against a bug where a single block with a repeated hash halts the entire network.
- Sepolia October 6: The Glamsterdam fork date on Sepolia was set to October 6, 2026, and the Hoodi date was left to be decided later. This fixes the day the upgrade first runs on a public testnet.
Discussion
Why the 1,000-node non-finality devnet stalled
A 1,000-node devnet launched to experiment with non-finality conditions failed to regain finality right after the fork. The call discussed which clients failed, why, and how to recover.
EIP-8037 state gas bug, to be fixed before the fork
The call was the place to confirm final approval on whether to fix, before the fork, a cross-frame bug found in EIP-8037 state gas, which is already included in Glamsterdam.
Outcome: Final decision 00:14:05
Sepolia fork: September 28 or October 6?
A discussion to set the date for Glamsterdam's first run on a public testnet. With the non-finality devnet issue still open, the question was whether to fix the date now.
Outcome: Schedule decision 00:29:41
Hegotá tier ranking: how far should opinions go?
The call discussed the deadline and scope of the tier rankings each team will submit to prioritize candidate EIPs for the next fork, Hegotá.
Glossary
- SFI: Scheduled for Inclusion: the status in which inclusion in the fork is confirmed
- CFI: Considered for Inclusion: the status in which inclusion in the fork is under formal review
- PFI: Proposed for Inclusion: the status in which inclusion in the fork has been proposed and accepted as a candidate
- DFI: Declined for Inclusion, the status of having been dropped from fork candidates
- DevNet: A temporary test network where developers try upgrades in advance
- Finality: The point at which a block is finalized and can no longer be reverted. Non-finality tests experiment with the extreme situation in which it is lost
- Glamsterdam and Hegotá: The names of the next Ethereum hard fork and the one after it, respectively
- ACDC and ACDE: The All Core Devs calls where consensus layer and execution layer developers each meet every two weeks