I credit Hugo in my partials/head.html template with the following function. If you use software for free or donations, please consider doing so too:

{{ .Hugo.Generator }}

But since January it’s been throwing a warning:

Building sites … $TIME WARN Page's .Hugo is deprecated and will 
be removed in a future release. Use the global hugo function.

The official docs still show this as the correct syntax. But this forum thread by @zwbetz suggests one should change it to:

{{ hugo.Generator }}

This works without warnings. Note that it needs to be spelled lowercase, or you’ll get a different error:

Error: $FILE parse failed: template: $TEMPLATE:$LINE:
function "Hugo" not defined

Or if you replace it with something completely pointless:

Error: $FILE parse failed: template: $TEMPLATE:$LINE:
function "BirdIsTheWord" not defined