Getting Potential Closure Details Before Building

Currently for my build process, I use morph to deploy, and then after a switch, I run nix profile diff-closures --profile /nix/var/nix/profiles/system. This tells me the size of various parts of my closure (less important to me) and the version bumps and changes to all packages changed by this.

I would, in fact, like to know before I run any build, not just how many packages will be built, but what individual versions will be bumped and what differences there are from the current closure. Is there some magic nix command I don’t yet know to evaluate and compare my configuration and locally pinned nixpkgs to the current configuration and give me
discord: 0.0.26 → 0.0.27, libcap: 2.67 → 2.68, etc?