If GitHub Copilot for Xcode crashes or closes immediately when opening a specific project but works fine with others, the issue is likely due to cached data created by Copilot for that project. This issue is observed when agent mode is enabled for large projects.
To fix this, you can remove the Github Copilot cached data in following directory:
~/.config/github-copilot/xcode
Now, restart the Xcode and GitHub Copilot for Xcode app. This should fix the issue.
