Django rest framework: searching on annotated field using ModelViewSet

Question

how are you? :)

My question is about using django RF ViewSets, RF Filters, over annotated fields with custom Object Managers.

So I've got this class

class SomeClass(models.Model):

    this_does_not_matter = models.CharField(max_length=50)
    objects = SomeClassManager()

with some manager with this shape

class SomeClassManager(models.Manager):

    def full_objs(self):
        qs = self.all()
        qs = qs.annotate(
            some_annotated_field=Count('this_dont_matter_either')
        )
        return qs

and finally, this viewSet

from rest_framework.viewsets import ModelViewSet
from rest_framework.filters import SearchFilter
...

class SomeClassViewSet(ModelViewSet):

    queryset = SomeClass.objects.full_objs()
    serializer_class = SomeClassSerializer
    filter_backends = (SearchFilter,)
    search_fields = ('some_annotated_field',)

and I get

SomeClass has no field named 'some_annotated_field'

even though i do get that field when asking for it to the api.

Question is: how do I get to search on some_annotated_field