How to cancel a macOS upgrade? (point release 10.12.x) I was told to upgrade my Xcode 9 to 9.1 but when I tried it in App Store it says 


  Xcode can’t be installed on “Macintosh HD” because macOS version 10.12.6 or later is required.


But that is not the problem, my OS is macOS 10.12.5 Sierra, I decided to click the Update button of Software Update  in App Store but when my computer is about to restart, I cancelled it when it prompts to close Terminal.

Why I cancelled it? It's because I remembered my Supervisor saying not to upgrade our OS. What should I do to cancel the update which is only waiting for my computer to restart? Me and my colleague has the same macOS but he doesn't have any problem upgrading Xcode. Please help!



P.S.
Hey guys I figured out there's really nothing to worry about because when I shut down my computer, there's a prompt saying wether I Shut Down or Install Updates and Shut Down. I chose Shut Down and that solves the problem. And also relating to the Xcode Upgrade problem, the answer is in the comment.
try deleting the .dmg file installer, maybe here  ~/Library/Application Support/AppStore but I'm not sure of the position.. also you can make a search of .dmg and order by date