Message Title

We are indexing two entities: Staff and RegistryReference. Only one index has sort fields declared - registry reference. They are declared as:

    @Field(name = "sort-date", index = Index.NO, analyze = Analyze.NO)
    @SortableField(forField = "sort-date")
    @DateBridge(resolution = Resolution.MILLISECOND)
    @Transient
    @SuppressWarnings("unused")
    private Date getIndexSortDate() {
        return RegistryReferenceIndexingServiceHolder.getRegistryReferenceIndexingService().getSortDate(this);
    }

        @Fields({
            @Field(name = "unstructured-address-ngram", analyzer = @Analyzer(definition = "ngram")),
            @Field(name = "unstructured-address-plain", analyzer = @Analyzer(definition = "plain")),
            @Field(name = "sort-address", index = Index.NO, analyze = Analyze.NO)
        })
        @SortableField(forField = "sort-address")
        private String unstructuredAddressDescription;

No problems there - indexing and searching seems to work fine. However, whenever I create a search for registry references, I get this warning in the log:

2018-12-18T10:28:34,468  WARN [http-apr-8080-exec-10] org.hibernate.search.reader.impl.ManagedMultiReader.getIndexesToBeUninverted(ManagedMultiReader.java:144) - HSEARCH000289: Requested sort field(s) addressBean.sort-address, sort-date are not configured for entity type ca.statcan.icos.model.admin.Staff mapped to index ca.statcan.icos.model.admin.Staff, thus an uninverting reader must be created. You should declare the missing sort fields using @SortableField.

Staff does not have those fields declared because... they aren't declared. But, I'm not searching Staff... so why do the sorts defined in my search for registry references trigger a warning for staff?