Ethereum developers confirmed a public test of the Glamsterdam upgrade on October 6, but warned that "fake builders" using free test Ether on the Sepolia testnet could stall the chain by overbidding and refusing to deliver transaction payloads. This action would not endanger mainnet funds but could hinder the infrastructure testing required before the Glamsterdam upgrade goes live on the Ethereum mainnet. Additionally, client teams have only seven days to release software before the Sepolia fork, half the usual 14-day security review period.