Ethereum Dates Glamsterdam's Sepolia Fork for 6 October

Ethereum's Glamsterdam upgrade now has a date on a public test network. The configuration merged into the Sepolia client repository sets activation at epoch 353024, slot 11296768, which works out to 6 October at 13:53:36 UTC. On a core developer call on Thursday, consensus developer Potuz described a cheap way to stall the test: free test ether makes builder identities disposable, and a builder that wins a block auction and then withholds the payload it promised takes the traffic with it. No mainnet funds are exposed. Client teams have until 29 September to ship software that runs the fork.

What a disposable builder costs

Enshrined proposer-builder separation, filed as EIP-7732, writes into the protocol the split between the validators that propose blocks and the parties that build them. Builders bid for the right to fill a block, and payload-timeliness committees check that the winner delivers what it sold. On Sepolia the bid costs nothing, because the ether does. Potuz put the problem in one breath.

"I can just spin up a thousand builders, rotate them, offer very high bids, and not produce payloads. Any teenager can do this," Potuz said.

CoinDesk and CoinCentral carry that sentence identically. crypto.news splits it into two fragments and paraphrases the middle, so the fuller wording is the one used here. The defence named on the call sits in the clients: software has to notice a builder that does not deliver, reject it, and fall back to a block it assembles locally. CoinDesk reports that builder software from the Titan and Ultrasound teams had not finished Glamsterdam support at the time of the call. No other account read for this piece repeats that, so it rests on one outlet.

Seven days to read the code

The review window is the other complaint on the call. Clients are due to release Sepolia-ready builds on 29 September, which leaves seven days before the fork against Ethereum's usual fourteen. Three accounts carry both figures without variation. crypto.news names Fredrik Svantes as the developer who raised the compressed window and Alex Stokes as the one arguing for earlier releases; it is alone in naming either, and both attributions stand on that single account. The argument reported against the worry is that Sepolia runs a controlled validator set, which makes recovering from a bad fork there cheap.

What Devnet-11 showed

The private testing the October date rests on ran last week. Devnet-11 came up on 14 September and moved to Gloas, the consensus-layer half of the upgrade, on the 16th, with about 84,000 validators across a multi-client setup and no loss of finality. Earlier rounds were rougher. A KuCoin research note of 14 September, written before Devnet-11 started, lists unplanned non-finality on Devnet-9, edge cases in how EIP-8037 accounts for state gas across nested calls, and a block-level access list problem involving legacy accounts that hold storage but have never sent a transaction. That note is the only account read here carrying the bug list, and it predates the run the schedule now depends on. This desk covered the 300 million gas limit Devnet-7 tested in July; the upgrade's own target is 200 million, against roughly 60 million on mainnet today.

The date after this one

Hoodi, the second public test, is pencilled in for 27 October and waits on how Sepolia goes. Mainnet has no date at all. CoinDesk says it is unscheduled, cryptodaily and CoinCentral say the roadmap points at the fourth quarter with the upgrade still classified as in testing, and crypto.news reported on 11 September that December had been discussed and not settled. Those readings do not reconcile, and no mainnet epoch has been published anywhere. The engineer who filed the Sepolia configuration was precise about what had actually been checked, recording that parsing and cross-client consistency were verified but that "no client startup or live fork-transition test was run." Glamsterdam has moved before. Plataberget opened as its public testnet months ago and the schedule has slipped since. What is different now is that an epoch sits in the client configs.