[mise_en_place]

I actually disagree that they shouldn't allow alternatives for `which`. IMO, just provide all of them and let the user decide. I should be able to choose from GNU which, BSD which, busybox which, or an alias to `command -v`. Default just keep it as GNU which.

[xg15]

In that case, have fun finding out which particular version is needed by the next install script you want to run.