I discovered this package by accident because I named a similar tool I am working on hackage-diff.

The specific problem I was trying to solve with my tool is to be able to run a command in a project directory and figure out if what is in that directory is the same as the latest version of the package on hackage. If not, it means I probably need to upload a new version to hackage. I maintain a lot of packages, and often when a new version of text, etc, comes out I have to make mods to many, but not all of the packages. But, by the time I am done making the mods, building them in the continuous integration server, etc, I've long forgotten which packages I modified and need to upload. :)

Your tool seems to have a lot of extra, useful features that would be helpful for assigning a new version number, etc. But, it seems to require that you specify an exact version number for the package to compare against on hackage.

Do you think it is reasonable that we could merge our tools into a single unified tool?

I have uploaded my work in progress here:

https://github.com/stepcut/hackage-whatsnew