Nightly Release Failed for on 2026-07-31

[github-actions]

The nightly-release workflow failed. See the full run for details: https://github.com/google-gemini/gemini-cli/actions/runs/30594112869

[gemini-cli]

Effort Analysis:
The release-nightly.yml workflow failed during the release job. The empty ${RELEASE_TAG} in the issue title ('Nightly Release Failed for on 2026-07-31') indicates the failure occurred before the Get Nightly Version step, specifically within the Run Tests step which executes the integration test suite via .github/actions/run-tests/action.yml. The root cause is a regression in packages/core/src/core/geminiChat.ts introduced in PR #28509. The getHistoryTurns function (lines 960-980) utilizes stripThoughts (lines 1528-1545) to prune history when context management is disabled for modern Gemini models. stripThoughts indiscriminately filters out all parts containing a thought property, which inadvertently removes the thought_signature metadata. The Gemini API requires this signature to be preserved in the conversation history for any functionCall generated by a reasoning turn; its absence triggers a 400 INVALID_ARGUMENT API error. Fixing this requires a non-trivial adjustment to the history filtering logic to selectively preserve required signatures and rigorous verification against the live Gemini API via integration tests, making it a medium-effort task.

[gemini-cli]

Please verify if this issue persists in the latest CLI version (0.55.0).