SolrEntityProcessor as SubEntity doesn't work with delta-import

<dataConfig>
    <document name="products">
        <entity
            name="outer"
            dataSource="my_datasource"
            pk="id"
            query="..."
            deltaQuery="..."
            deltaImportQuery="..."
        >
            <entity
                name="solr"
                processor="SolrEntityProcessor"
                url="http://127.0.0.1:8983/solr/${solr.core.name}"
                query="Xid:${outer.Xid}"
                rows="1"
                fl="Id,FieldA,FieldB"
                wt="javabin"
            />
        </entity>
    </document>
</dataConfig>

java.lang.RuntimeException: java.lang.RuntimeException: org.apache.solr.handler.dataimport.DataImportHandlerException: java.lang.IllegalStateException: Connection pool shut down
    at org.apache.solr.handler.dataimport.DocBuilder.execute(DocBuilder.java:270)
    at org.apache.solr.handler.dataimport.DataImporter.doDeltaImport(DataImporter.java:444)
    at org.apache.solr.handler.dataimport.DataImporter.runCmd(DataImporter.java:482)
    at org.apache.solr.handler.dataimport.DataImporter$1.run(DataImporter.java:461)
Caused by: java.lang.RuntimeException: org.apache.solr.handler.dataimport.DataImportHandlerException: java.lang.IllegalStateException: Connection pool shut down
    at org.apache.solr.handler.dataimport.DocBuilder.buildDocument(DocBuilder.java:416)
    at org.apache.solr.handler.dataimport.DocBuilder.doDelta(DocBuilder.java:363)
    at org.apache.solr.handler.dataimport.DocBuilder.execute(DocBuilder.java:224)
    ... 3 more
Caused by: org.apache.solr.handler.dataimport.DataImportHandlerException: java.lang.IllegalStateException: Connection pool shut down
    at org.apache.solr.handler.dataimport.DataImportHandlerException.wrapAndThrow(DataImportHandlerException.java:62)
    at org.apache.solr.handler.dataimport.EntityProcessorWrapper.nextRow(EntityProcessorWrapper.java:246)
    at org.apache.solr.handler.dataimport.DocBuilder.buildDocument(DocBuilder.java:475)
    at org.apache.solr.handler.dataimport.DocBuilder.buildDocument(DocBuilder.java:514)
    at org.apache.solr.handler.dataimport.DocBuilder.buildDocument(DocBuilder.java:414)
    ... 5 more
Caused by: java.lang.IllegalStateException: Connection pool shut down
    at org.apache.http.util.Asserts.check(Asserts.java:34)
    at org.apache.http.pool.AbstractConnPool.lease(AbstractConnPool.java:184)
    at org.apache.http.pool.AbstractConnPool.lease(AbstractConnPool.java:217)
    at org.apache.http.impl.conn.PoolingClientConnectionManager.requestConnection(PoolingClientConnectionManager.java:184)
    at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:415)
    at org.apache.http.impl.client.AbstractHttpClient.doExecute(AbstractHttpClient.java:882)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:82)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:107)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:55)
    at org.apache.solr.client.solrj.impl.HttpSolrClient.executeMethod(HttpSolrClient.java:466)
    at org.apache.solr.client.solrj.impl.HttpSolrClient.request(HttpSolrClient.java:235)
    at org.apache.solr.client.solrj.impl.HttpSolrClient.request(HttpSolrClient.java:227)
    at org.apache.solr.client.solrj.SolrRequest.process(SolrRequest.java:135)
    at org.apache.solr.client.solrj.SolrClient.query(SolrClient.java:943)
    at org.apache.solr.client.solrj.SolrClient.query(SolrClient.java:958)
    at org.apache.solr.handler.dataimport.SolrEntityProcessor.doQuery(SolrEntityProcessor.java:198)
    at org.apache.solr.handler.dataimport.SolrEntityProcessor.buildIterator(SolrEntityProcessor.java:147)
    at org.apache.solr.handler.dataimport.SolrEntityProcessor.nextRow(SolrEntityProcessor.java:128)
    at org.apache.solr.handler.dataimport.EntityProcessorWrapper.nextRow(EntityProcessorWrapper.java:243)
    ... 8 more