Worked on the picnixz/cpython repository to enhance the robustness of Python dataclasses, specifically addressing issues with ClassVar detection when types are re-exported from modules outside of typing. Focused on improving type annotation handling to support cross-module re-exports, this work ensured that custom type imports functioned correctly across diverse import scenarios. The solution involved careful updates to the dataclass implementation, reducing edge-case failures for downstream users who rely on complex module structures. Leveraged Python, software development best practices, and unit testing to validate the fix, resulting in more reliable dataclass behavior in projects with advanced type usage patterns.