ACDT #96 · Sepolia Glamsterdam Confirmed for Oct 6
AllCoreDevs - Testing #096 · 2026-09-14
The next hard fork enters its first public testnet stage
The Sepolia Glamsterdam upgrade was confirmed for Oct 6 with the agreement of all clients. On the day of the call, Glamsterdam activated on devnet 11 with no drop in participation, a green light for the schedule.
Why it matters
With Glamsterdam entering the public testnet stage, the timeline to mainnet has become more concrete. Large protocols such as Lido and Optimism are already validating the upgrade on devnets, so it is time for L2s and staking services to start preparing.
Decisions
- Sepolia October 6: The Sepolia Glamsterdam upgrade was set for Oct 6 and all clients agreed. This means the next hard fork enters real-world validation on a public testnet.
- Spec test restriction: It was decided that only tests for CFI and SFI stage EIPs will be added to the trunk branch of the consensus-specs repository. For PFI stage proposals, this means tests should be prepared in a fork or a PR in advance.
- Shadow fork schedule: The Sepolia shadow fork is targeted for next week, and client readiness will be checked again on the next ACDT. A shadow fork is a procedure that clones a real network to rehearse the upgrade.
- Legacy test restoration: Legacy tests PR #18 will be merged to revert to the collision handling of the Yellow Paper and EIP-684. Collision handling for the Block Access List (BAL) is left undefined until EIP-8253 in Hegota is settled.
- EIP-8038 wording: PR EIPs#12317, which concerns the SELFDESTRUCT beneficiary in EIP-8038, was approved as an EIP wording clarification. Nothing changes in the spec or in client behavior.
- EIP-8037 merge: PR EIPs#12311, which states the total state gas limit explicitly in EIP-8037, was merged. Client behavior stays the same and only a small addition to the spec is needed.
Discussion
Devnet 8 recovery and cross-layer coordination
After a week of attack testing, devnet 8 was slow to recover, and the question of who will track problems and coordinate came up.
Restricting consensus spec test additions
Because tests for EIPs that anyone can propose were touching many parts of the specs repository and increasing the maintenance burden, a proposal was made to limit which EIPs can add tests to the trunk.
Outcome: Decision confirmed 00:19:11
Sepolia shadow fork start time
The discussion was about when to launch the shadow fork, a rehearsal before the Sepolia upgrade, and client readiness was the key issue.
Outcome: Schedule decision 00:18:24
EIP-7610 rollback and BAL collision handling
After EIP-7610, which does not define contract creation collision handling, broke many legacy tests, the discussion covered whether to revert to the old behavior and how the newly introduced BAL should handle this case.
Outcome: Decision confirmed 00:35:09
Glossary
- SFI: Scheduled for Inclusion, the EIP stage where inclusion in the next fork is confirmed
- CFI: Considered for Inclusion, the stage where inclusion in the fork is under review
- PFI: Proposed for Inclusion, the stage where inclusion has been proposed and the EIP has been accepted as a candidate
- DFI: Declined for Inclusion, the stage where an EIP is excluded from fork candidacy
- BAL: Block Access List, a list that summarizes state changes by enumerating the accounts and storage a block touched
- Shadow fork: A temporary fork (shadow fork) that clones real network state to rehearse an upgrade in advance
- Devnet: A temporary development network (devnet) for testing features under development
- EL/CL: The Execution Layer and the Consensus Layer, the two software layers that make up an Ethereum node