Hey, thanks for the report. Handling of sandbox environment variables like CARGO_HOME and RUSTUP_HOME has improved in recent updates, and build cache sharing has also gotten better to avoid full recompiles.
Can you share your Cursor version? (Help > About or cursor --version). If you’re already on the latest version, try removing the Cursor workaround rule and run a clean cargo build in the sandbox. The fix might already cover your case.
Let me know how it goes after updating, if an update is needed.