                          "name": index_name,
                      }
                  )
          # Drop any FK constraints, we'll remake them later
          if getattr(old_field, "rel"):
              fk_names = self._constraint_names(model, [old_field.column], foreign_key=True)
              if strict and len(fk_names) != 1:
                  raise ValueError("Found wrong number (%s) of foreign key constraints for %s.%s" % (
                      len(fk_names),
                      model._meta.db_table,
 
</s> remove         if getattr(new_field, "rel"):
 </s> add         if new_field.rel: </s> remove                 if hasattr(field, "rel"):
                    if hasattr(field.rel, "to"):
 </s> add                 if field.rel:
                    if field.rel.to:
        if old_field.rel:
                          "name": index_name,
                      }
                  )
          # Drop any FK constraints, we'll remake them later
        if old_field.rel:
              fk_names = self._constraint_names(model, [old_field.column], foreign_key=True)
              if strict and len(fk_names) != 1:
                  raise ValueError("Found wrong number (%s) of foreign key constraints for %s.%s" % (
                      len(fk_names),
                      model._meta.db_table,
keep keep keep keep replace keep keep keep keep keep
 Stop being overcautious about Field.rel 
django/db/backends/schema.py