tests@v21.0.0

This is our first mainnet fixture release to include Amsterdam, targeting the Glamsterdam upgrade on Sepolia on 6 October 2026 at 13:53:36 UTC. It extends the tests@v20.0.2 series through Amsterdam and is built from the forks/amsterdam branch.

This release follows our first full, in-depth review across all 15 Glamsterdam EL EIPs, including spec/EELS alignment, coverage analyses, mutation checks and cross-EIP interactions. The full scope and PRs are tracked in the test release tracker (#3217), so PTAL!

Key Updates

• Amsterdam coverage: a net increase of 828 unique parameterised test cases compared with tests-glamsterdam-devnet@v8.1.4, from 3,996 to 4,824 (about 21%). Each case is counted once across state, blockchain, Engine and Engine X formats. These are collection counts excluding explicitly skipped and execute-only cases.
• Expanded coverage for gas boundaries, refunds, authorization rollback, contract creation, SELFDESTRUCT, BALs, system contracts and fork transitions. See the tracker for the full per-EIP additions.
• Ported static tests: all remaining tests on the Amsterdam skip list are enabled and the list is removed (#3322).
• EIP-8037: total transaction gas is capped at 2^32 - 1, including the state-gas reservoir, with boundary and fork-transition tests (#3582).
• Contract creation: fix EELS storage clearing from Cancun onward when deploying over a storage-only account, with regression tests for the removal of the EIP-7610 storage-collision check (#3508).
• Corrected EELS BAL change netting for system calls that undo each other, with new regression tests (#3566).

We expect one or two follow-up releases before mainnet, incorporating client testing feedback, additional coverage and fixes found during testnet testing.

Full Changelog: https://github.com/ethereum/execution-specs/compare/tests@v20.0.2...tests@v21.0.0