🚨 Mandatory Testnet (atlantic-2) Upgrade — v6.6

⚠️ This is a MANDATORY upgrade for all atlantic-2 testnet node operators and validators. Nodes that do not upgrade will halt at the upgrade height and fall out of consensus.

📋 Upgrade Summary

Note: The on-chain Upgrade Name (v6.6) is intentionally different from the git tag (v6.6.0-rc5). Cosmovisor matches on the Upgrade Name, so the directory must be named v6.6 — see below.

✅ What Operators Need to Do

1. Build / download the new binary from this release (v6.6.0-rc5).
2. Wait for the chain to halt automatically at height 262193175. Do not stop your node manually before this height.
3. Swap in the new binary and restart your node once the halt occurs.
4. Confirm your node resumes producing/syncing blocks past the upgrade height.

💡 Cosmovisor users: place the new binary under upgrades/v6.6/bin/ (using the upgrade name, not the git tag) ahead of time, and the switch will happen automatically at the upgrade height.

What's Changed

• Backport release/v6.6: fix(giga): route EVM validation failures to v2 fallback (CON-368) by @seidroid[bot] in https://github.com/sei-protocol/sei-chain/pull/3757
• Backport release/v6.6: Update v6.6 changelog in prep to cut rc3 by @seidroid[bot] in https://github.com/sei-protocol/sei-chain/pull/3746
• Bump version in prep to release v6.6-rc4 by @bdchatham in https://github.com/sei-protocol/sei-chain/pull/3766
• Backport release/v6.6: fix(giga): fall back to v2 on execution errors by @seidroid[bot] in https://github.com/sei-protocol/sei-chain/pull/3781
• Backport release/v6.6: Update v6.6 changelog in prep to cut rc4 by @seidroid[bot] in https://github.com/sei-protocol/sei-chain/pull/3782

Full Changelog: https://github.com/sei-protocol/sei-chain/compare/v6.6.0-rc3...v6.6.0-rc5