Clarity Upgrade Failure: Can a Failed Multi-Step Migration Leave Partial State?

Clarity Upgrade Failure

When upgrading a Stacks smart contract, the developer often splits the migration into multiple sequential transactions. The goal is to preserve contract state while applying new logic. However, Clarity’s atomicity guarantees apply only to individual transactions. If a second migration step fails, it is unclear whether the first step’s state changes are automatically rolled back or remain on-chain. This uncertainty can lead to an inconsistent contract state that is difficult to recover from.

Constraints:

• Clarity contracts are immutable; upgrades require deploying a new contract and migrating state explicitly.
• There is no built‑in cross‑contract or multi‑step rollback mechanism.
• Fee handling for aborted calls may differ across Stacks node releases.

Uncertainty:

• Does a failure in a later migration step automatically revert all prior successful steps?
• What is the fee‑charging behavior for aborted calls in the target node version?
• Are there recommended patterns to ensure atomicity across a multi‑step upgrade?

Specific questions:

1. Does Clarity provide any mechanism to roll back all steps of a multi‑step migration if any step fails?
2. How does fee handling differ for aborted calls in various Stacks node releases?
3. What best‑practice patterns can developers use to maintain state consistency across upgrade steps?