Part of djust 1.3 — read the 1.3 release notes.
Fixed
{% regroup %}over a single model refuses, as Django does (#3948). A model is not iterable, so{% regroup r by name as g %}over one raisesTypeError; through a LiveView's state the tag was handed the model's serialized map and grouped its key names. The tag now refuses a source that is a serialized model map (a text__str__, a text__model__and apk), after any filters on the source have run. A regroup over a list, tuple or QuerySet of models, and over an ordinary dict, is unchanged. Pinned against Django on a real instance inpython/tests/test_regroup_model_source_3948.py.