Antoine Cousson [off-list ref] writes:

I would like to say that I still use `git whatchanged` I like the way we see the
modified files instead of just `git log`

Then perhaps you would like "git log --stat" even better?  Instead
of meaningless pair of hexadecimal object names, you'd get a sense
of the size of damage each commit causes to the codebase.

The command is going away.  You could

  $ git config alias.whatchanged "log --raw --no-merges"

if you really prefer the ugly hexadecimal gibberish, though.