How to find out why iTerm2 suddenly wants to access my Calendar?
From an open issue on the linked iTerm2 project page on GitLab:


iTerm asks for contacts and calendar access on Mac OS



  I tested version 3.2.6 on macOS 10.14. It does not request contacts or calendars in a stock install. If you run a program in your .bashrc or other login script that needs access to such (e.g., icalBuddy) then it will be asked for in iTerm2's name.





  Anything inside the terminal that tries to access just some calendar file ou directory will initiate the MacOS dialog asking for permission. But that does not mean iTerm is trying to access.
  
  Thy this command:
  
  $ find /
  
  It will list all your directories, and.. there will be a moment that MacOS will ask you for permission to let iTerm access your calendar. Lol.. this is a funny erroneous comportamental feature of MacOS..




As is apparent, from the comment, the -d 1 component of the command line attempted to access Calendar files, thereby triggering the permission dialogue.