Ethereum developers targeted October 9 for Constantinople’s Ropsten test

Ethereum core developers used their September 14, 2018 coordination call to target approximately October 9 for testing the Constantinople hard fork on Ropsten, Ethereum’s public proof-of-work test network. They did not lock an activation block or a mainnet date. Instead, they chose a working test window and said the block number would be set at their next meeting two weeks later.

That distinction mattered. Constantinople would change the consensus rules followed by Ethereum clients, so a safe production deployment depended on different software teams implementing and testing the same behavior. Ropsten offered a public rehearsal using a chain with existing activity, without placing mainnet ether balances at risk.

A target, not a launch commitment

The official notes for AllCoreDevs meeting 46 record the September 14 call at 14:00 UTC. During the Constantinople discussion, participants considered whether to use Ropsten or create another test network. Developers favored Ropsten because its activity made it useful for testing a live chain transition, even though its block times were unstable.

The resulting plan was deliberately approximate: aim for October 9, then calculate a block height closer to the event. No Constantinople code activated on September 14. The mainnet fork was discussed as potentially feasible in November or December, but no production block was selected.

Readiness was uneven. Parity and Aleth reported that the Constantinople proposals had been implemented, while Geth, Trinity, Harmony/EthereumJ and other clients still described unfinished work or testing gaps. The notes also recorded 52 failures in one Geth run of the Hive cross-client test system, with uncertainty over whether the tests had been generated correctly. These were development observations, not proof of 52 distinct protocol defects.

What Constantinople was designed to change

The upgrade package combined five principal Ethereum Improvement Proposals. EIP-145 added native bitwise-shift operations. EIP-1014 introduced CREATE2, allowing a contract address to be derived from specified inputs before the contract existed on-chain. EIP-1052 added EXTCODEHASH so contracts could inspect a hash of another account’s code without copying all of that code. EIP-1283 revised gas accounting for contract-storage changes.

EIP-1234 carried the clearest economic consequence. It proposed reducing the base block reward from 3 ETH to 2 ETH and delaying the “difficulty bomb” by roughly 12 months. The bomb was a programmed increase in proof-of-work difficulty intended to make continued mining progressively slower. Delaying it preserved workable block production while the planned shift toward proof of stake remained unfinished; cutting the reward limited the issuance increase that a delay would otherwise create.

These specifications described intended protocol rules. They did not establish that miners, exchanges or node operators had accepted a future mainnet fork.

Market context and limits

Kraken’s September 14 daily report recorded ETH at $217.80, up 7.22%, with $75.4 million traded on the exchange; it recorded BTC at $6,518, up 1.21%, with $53.8 million traded. Kraken reported $152 million across all of its markets.

Those are venue-specific daily figures covering Kraken’s crypto and fiat pairs, not a consolidated global close. The surviving report does not define its exact cutoff, price construction or whether its percentage change used a uniform 24-hour window. The figures show that the scheduling discussion occurred during an ether rebound, but they do not prove that the developer call caused the move.

Later context

The October 9 target did not hold. A block number was subsequently set for Ropsten, and the Constantinople test reached block 4,230,000 on October 13, 2018 amid mining-coordination and consensus problems. Mainnet activation came only later, on February 28, 2019, paired with the St. Petersburg upgrade. Those outcomes were not knowable on September 14 and do not change the event-day fact: developers had established a public testing direction while significant implementation and coordination work remained.