Command line query tools can cause NPE.

java.lang.NullPointerException
    at org.apache.jena.query.QueryExecutionFactory.make(QueryExecutionFactory.java:615)
    at org.apache.jena.query.QueryExecutionFactory.create(QueryExecutionFactory.java:94)
    at arq.query.lambda$queryExec$0(query.java:224)
    at org.apache.jena.system.Txn.exec(Txn.java:77)
    at org.apache.jena.system.Txn.executeRead(Txn.java:115)
    at arq.query.queryExec(query.java:222)
    at arq.query.exec(query.java:153)
    at jena.cmd.CmdMain.mainMethod(CmdMain.java:93)
    at jena.cmd.CmdMain.mainRun(CmdMain.java:58)
    at jena.cmd.CmdMain.mainRun(CmdMain.java:45)
    at arq.arq.main(arq.java:28)