What does lsboxd process do on os x?
Solution 1:
lsboxd is part of the OS X Sandbox.
It allows communication between sandboxed applications.
lsboxd is in the Launch Services API. It is the Launch Services Sandbox Daemon, which governs what apps can launch apps in the OS X sandbox. You can peruse the App Sandbox Guide for more information about sandboxing.
Solution 2:
Go to System Preferences > Security & Privacy > Calendars and uncheck the box next to the lsboxd
Why this part of XCode needs access to your Calendar, is a different story.