Constant MAX_TRANSACTIONS_PER_BLOCK 

pub const MAX_TRANSACTIONS_PER_BLOCK: usize = _; // 66_666usize

Upper bound on the number of transactions in any consensus-valid block.

Consensus does not fix a tx-count limit; it follows from MAX_BLOCK_WEIGHT (BIP141). Mainnet has included blocks with 12k+ transactions (e.g. dense 2015–2016 spam eras); a 10k cap incorrectly rejects valid blocks and panicked in compute_block_tx_ids.

Uses a loose per-tx minimum weight (~60 WU) so MAX_BLOCK_WEIGHT / 60 safely exceeds any block that could pass weight check (real minimum per tx is higher).