SingleObjectMixin raises misleading AttributeError when called witout pk or slug

[oliver]

class FooUpdateView(django.views.generic.UpdateView):
    model = Foo
    form_class = FooForm
    template_name = 'foo.html'

urlpatterns = [
    url(^'foo/$', FooUpdateView,as_view(), name='detal'),
]

In above code, If a user calls foo/, following AttributeError will be raised.
Generic detail view FooUpdateView must be called with either an object pk or a slug in the URLconf.

FooUpdateView raises the error even though it isn't generic detail view.
Also CreateView has this issue because it inherits from SingleObjectMixin.

[oliver]

​https://github.com/django/django/pull/10742

[Carlton Gibson]

The error message here has been unchanged since class-based views were first introduced in 0fcb09455729113f64a9873ca40bffd009b9bc5f for #6735.

The phrasing "generic detail view" captures not a specific view class but the group of all descendants of SingleObjectMixin (otherwise it would be GenericDetailView...) There are (I think) 11 of those. It reflects the view.generic.detail module naming. I think it's fine vs the proposed that inherits from SingleObjectMixin alteration.