2026-04 Monthly summary for aiida-core. Focused on stabilizing the API test suite to enable faster, safer iterations and refactors. Key features delivered: - API Test Stabilization (bug fix): Replaced recwarn with warnings.catch_warnings scoped to DeprecationWarning to ensure only DeprecationWarnings are targeted, preventing unrelated ResourceWarnings from inflating test failure counts. Major bugs fixed: - Flaky test results due to uncaptured or miscounted warnings were eliminated by targeted warning handling, improving reliability of test_api across Python versions including Python 3.14. Overall impact and accomplishments: - Significantly improved CI reliability and determinism of the aiida-core test suite, accelerating development velocity and safer code changes. - Reduced time spent diagnosing flaky tests, enabling faster feedback for contributors. Technologies/skills demonstrated: - Python warnings API (warnings.catch_warnings) and context management - Test isolation strategies to improve reliability across Python versions - Cross-version compatibility considerations (Python 3.14) and CI stability

August 2025 (aiida-core): Focused on stabilizing test reliability for data exporter functionality by exploring filesystem isolation strategies in CI. An experimental approach ran the data_exporters tests in a temporary directory to mitigate filesystem interference, with commits 01a4dcd170c2b8b5180e44447a5e71be46fe49b1 (Hack: Run `test_data_exporters` in tmp_dir) and ec7bde84188366c56036ae94daa9a6a4a4990434 (Revert "Hack: Run `test_data_exporters` in tmp_dir"). The work helped characterize flaky-test risks and yielded actionable learnings, though the final approach was reverted to align with the standard test environment. No user-facing features were released this month; instead, the focus was on improving CI stability and test determinism for data export workflows.