[cstrahan]

> All of the above?

Nope.

At best, you can do something like this: apt-get install gparted=0.16.1-1

That handles the semver case, but that doesn't address the rest of the "all of the above":

- sha256 calculated by the content of the package (Content Addressed)

- checksum calculated from all the inputs that were used to create the package install spec (Input Addressed)

> Nix isn’t the first package manager to do something unique.

Sure. But it is the first package manager to do the above unique things. After all, the reason for Nix's existence is just that: no other package manager before it has done what it does.