solr SQL throwing an exception

[datadavev]

The solr sql endpoint (/solr/isb_core_records/sql) throws an exception:

{
  "error":{
    "metadata":["error-class","org.apache.solr.common.SolrException","root-error-class","java.lang.ClassNotFoundException"],
    "msg":" Error loading class 'solr.SQLHandler'",
    "trace":"org.apache.solr.common.SolrException:  Error loading class 'solr.SQLHandler'\n\tat org.apache.solr.core.SolrResourceLoader.findClass(SolrResourceLoader.java:550)\n\tat org.apache.solr.core.SolrResourceLoader.findClass(SolrResourceLoader.java:471)\n\tat org.apache.solr.core.SolrCore.createInstance(SolrCore.java:939)\n\tat org.apache.solr.core.PluginBag$LazyPluginHolder.createInst(PluginBag.java:520)\n\tat org.apache.solr.core.PluginBag$LazyPluginHolder.get(PluginBag.java:502)\n\tat org.apache.solr.core.PluginBag.get(PluginBag.java:198)\n\tat org.apache.solr.handler.RequestHandlerBase.getRequestHandler(RequestHandlerBase.java:315)\n\tat org.apache.solr.core.SolrCore.getRequestHandler(SolrCore.java:1984)\n\tat org.apache.solr.servlet.HttpSolrCall.extractHandlerFromURLPath(HttpSolrCall.java:429)\n\tat org.apache.solr.servlet.HttpSolrCall.init(HttpSolrCall.java:325)\n\tat org.apache.solr.servlet.HttpSolrCall.call(HttpSolrCall.java:509)\n\tat org.apache.solr.servlet.SolrDispatchFilter.dispatch(SolrDispatchFilter.java:262)\n\tat org.apache.solr.servlet.SolrDispatchFilter.lambda$doFilter$0(SolrDispatchFilter.java:219)\n\tat org.apache.solr.servlet.ServletUtils.traceHttpRequestExecution2(ServletUtils.java:246)\n\tat org.apache.solr.servlet.ServletUtils.rateLimitRequest(ServletUtils.java:215)\n\tat org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:213)\n\tat org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:195)\n\tat org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:210)\n\tat org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1635)\n\tat org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:527)\n\tat org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:131)\n\tat org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:598)\n\tat org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:122)\n\tat org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:223)\n\tat org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1580)\n\tat org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:221)\n\tat org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1384)\n\tat org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:176)\n\tat org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:484)\n\tat org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1553)\n\tat org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:174)\n\tat org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1306)\n\tat org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:129)\n\tat org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:149)\n\tat org.eclipse.jetty.server.handler.InetAccessHandler.handle(InetAccessHandler.java:228)\n\tat org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:141)\n\tat org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:122)\n\tat org.eclipse.jetty.rewrite.handler.RewriteHandler.handle(RewriteHandler.java:301)\n\tat org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:122)\n\tat org.eclipse.jetty.server.handler.gzip.GzipHandler.handle(GzipHandler.java:822)\n\tat org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:122)\n\tat org.eclipse.jetty.server.Server.handle(Server.java:563)\n\tat org.eclipse.jetty.server.HttpChannel$RequestDispatchable.dispatch(HttpChannel.java:1598)\n\tat org.eclipse.jetty.server.HttpChannel.dispatch(HttpChannel.java:753)\n\tat org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:501)\n\tat org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:287)\n\tat org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:314)\n\tat org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:100)\n\tat org.eclipse.jetty.io.SelectableChannelEndPoint$1.run(SelectableChannelEndPoint.java:53)\n\tat org.eclipse.jetty.util.thread.strategy.AdaptiveExecutionStrategy.runTask(AdaptiveExecutionStrategy.java:421)\n\tat org.eclipse.jetty.util.thread.strategy.AdaptiveExecutionStrategy.consumeTask(AdaptiveExecutionStrategy.java:390)\n\tat org.eclipse.jetty.util.thread.strategy.AdaptiveExecutionStrategy.tryProduce(AdaptiveExecutionStrategy.java:277)\n\tat org.eclipse.jetty.util.thread.strategy.AdaptiveExecutionStrategy.run(AdaptiveExecutionStrategy.java:199)\n\tat org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:411)\n\tat org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:969)\n\tat org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.doRunJob(QueuedThreadPool.java:1194)\n\tat org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:1149)\n\tat java.base/java.lang.Thread.run(Unknown Source)\nCaused by: java.lang.ClassNotFoundException: solr.SQLHandler\n\tat java.base/java.net.URLClassLoader.findClass(Unknown Source)\n\tat java.base/java.lang.ClassLoader.loadClass(Unknown Source)\n\tat java.base/java.net.FactoryURLClassLoader.loadClass(Unknown Source)\n\tat java.base/java.lang.ClassLoader.loadClass(Unknown Source)\n\tat java.base/java.lang.Class.forName0(Native Method)\n\tat java.base/java.lang.Class.forName(Unknown Source)\n\tat org.apache.solr.core.SolrResourceLoader.findClass(SolrResourceLoader.java:534)\n\t... 57 more\n",
    "code":500
  }
}

The config api (api/collections/isb_core_records/config) indicates that the extension is enabled:

...
      "/sql":{
        "class":"solr.SQLHandler",
        "startup":"lazy",
        "useParams":"_SQL",
        "invariants":{"distrib":false},
        "name":"/sql"},
...

So perhaps there's a missing jar file? The docs seem to suggest that this is part of the normal distribution, but perhaps there's something that needs to be included with the docker image?