IsSet with unsupported type "invalid"

8:58:59 PM: WARNING: calling IsSet with unsupported type "invalid" (<nil>) will always return false.

The above is all Hugo is telling me when it got an issue with… ehm… something. I searched for all occurences with IsSet but found none that looks like nil. What should be my procedure to narrow the location of the issue? The way I understand it something is always not defined.

Couldn’t Hugo somehow give more info on where that happens? It would be nice to have a setting that let’s Hugo print a “stacktrace” for warnings?