The newest upgrade to the Ethereum network, codenamed “Cancun-Deneb” or “Dencun,” has gone live on the Goerli testnet for the first time, according to a Jan. 17 social media post from Ethereum developer Parithosh Jayanthi.

According to Jayanthi, a bug delayed the network’s launch for approximately four hours. But once this problem was fixed through a patch, the network came back up.

Once implemented on mainnet, the Dencun upgrade will significantly lower the cost of transactions on Ethereum layer-2s such as Optimism, Base, Polygon zkEVM, and others, developers have claimed. It will also limit self-destruct operations and allow for new bridge and staking pool features.

The fork was implemented at approximately 6 am UTC, according to Ethereum developer Tim Beiko. About 20 minutes after this post, Beiko announced that the network had undergone a “chain split” due to a lack of finalization. Terence.eth later revealed that the Prysm implementation of Ethereum contained a bug causing it to fail to sync with the other nodes. Once the bug was discovered and patched, the network began running smoothly again, according to Jayanthi.

Jayanthi claimed that the quickly implemented solution was a testament to the power of the team’s debugging systems. “I do want to mention that we went from fork -> issue -> triage -> fix -> finality in under 4h,” Jayanthi stated. “The debugging apparatus has gotten great!”

According to Dencun’s testing schedule, its next big moment will be Jan. 30, when it is slated to be implemented on the Sepolia testnet. Holesky testnet will follow on Feb. 7. The team has not yet announced a date for the upgrade to be implemented on mainnet.