An error was encountered:
An error occurred while calling z:is.hail.backend.spark.SparkBackend.apply.
: org.apache.spark.SparkException: Only one SparkContext should be running in this JVM (see SPARK-2243).The currently running SparkContext was created at:
org.apache.spark.SparkContext.getOrCreate(SparkContext.scala)
org.apache.livy.rsc.driver.SparkEntries.sc(SparkEntries.java:53)
org.apache.livy.rsc.driver.SparkEntries.sparkSession(SparkEntries.java:67)
org.apache.livy.repl.AbstractSparkInterpreter.postStart(AbstractSparkInterpreter.scala:69)
org.apache.livy.repl.SparkInterpreter.$anonfun$start$1(SparkInterpreter.scala:90)
scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:23)
org.apache.livy.repl.AbstractSparkInterpreter.restoreContextClassLoader(AbstractSparkInterpreter.scala:340)
org.apache.livy.repl.SparkInterpreter.start(SparkInterpreter.scala:63)
org.apache.livy.repl.Session.$anonfun$start$1(Session.scala:128)
scala.concurrent.Future$.$anonfun$apply$1(Future.scala:659)
scala.util.Success.$anonfun$map$1(Try.scala:255)
scala.util.Success.map(Try.scala:213)
scala.concurrent.Future.$anonfun$map$1(Future.scala:292)
scala.concurrent.impl.Promise.liftedTree1$1(Promise.scala:33)
scala.concurrent.impl.Promise.$anonfun$transform$1(Promise.scala:33)
scala.concurrent.impl.CallbackRunnable.run(Promise.scala:64)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
java.lang.Thread.run(Thread.java:748)
	at org.apache.spark.SparkContext$.$anonfun$assertNoOtherContextIsRunning$2(SparkContext.scala:2672)
	at scala.Option.foreach(Option.scala:407)
	at org.apache.spark.SparkContext$.assertNoOtherContextIsRunning(SparkContext.scala:2669)
	at org.apache.spark.SparkContext$.markPartiallyConstructed(SparkContext.scala:2759)
	at org.apache.spark.SparkContext.<init>(SparkContext.scala:96)
	at is.hail.backend.spark.SparkBackend$.configureAndCreateSparkContext(SparkBackend.scala:146)
	at is.hail.backend.spark.SparkBackend$.apply(SparkBackend.scala:222)
	at is.hail.backend.spark.SparkBackend.apply(SparkBackend.scala)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:244)
	at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:357)
	at py4j.Gateway.invoke(Gateway.java:282)
	at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:132)
	at py4j.commands.CallCommand.execute(CallCommand.java:79)
	at py4j.GatewayConnection.run(GatewayConnection.java:238)
	at java.lang.Thread.run(Thread.java:748)

Traceback (most recent call last):
  File "/usr/local/lib/python3.7/site-packages/hail/context.py", line 575, in _set_flags
    available = set(Env.backend()._jhc.flags().available())
  File "/usr/local/lib/python3.7/site-packages/hail/utils/java.py", line 67, in backend
    return Env.hc()._backend
  File "/usr/local/lib/python3.7/site-packages/hail/utils/java.py", line 55, in hc
    init()
  File "<decorator-gen-1821>", line 2, in init
  File "/usr/local/lib/python3.7/site-packages/hail/typecheck/check.py", line 577, in wrapper
    return __original_func(*args_, **kwargs_)
  File "/usr/local/lib/python3.7/site-packages/hail/context.py", line 252, in init
    skip_logging_configuration, optimizer_iterations)
  File "/usr/local/lib/python3.7/site-packages/hail/backend/spark_backend.py", line 174, in __init__
    jsc, app_name, master, local, True, min_block_size, tmpdir, local_tmpdir)
  File "/usr/lib/spark/python/lib/py4j-0.10.9-src.zip/py4j/java_gateway.py", line 1305, in __call__
    answer, self.gateway_client, self.target_id, self.name)
  File "/usr/lib/spark/python/lib/pyspark.zip/pyspark/sql/utils.py", line 111, in deco
    return f(*a, **kw)
  File "/usr/lib/spark/python/lib/py4j-0.10.9-src.zip/py4j/protocol.py", line 328, in get_return_value
    format(target_id, ".", name), value)
py4j.protocol.Py4JJavaError: An error occurred while calling z:is.hail.backend.spark.SparkBackend.apply.
: org.apache.spark.SparkException: Only one SparkContext should be running in this JVM (see SPARK-2243).The currently running SparkContext was created at:
org.apache.spark.SparkContext.getOrCreate(SparkContext.scala)
org.apache.livy.rsc.driver.SparkEntries.sc(SparkEntries.java:53)
org.apache.livy.rsc.driver.SparkEntries.sparkSession(SparkEntries.java:67)
org.apache.livy.repl.AbstractSparkInterpreter.postStart(AbstractSparkInterpreter.scala:69)
org.apache.livy.repl.SparkInterpreter.$anonfun$start$1(SparkInterpreter.scala:90)
scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:23)
org.apache.livy.repl.AbstractSparkInterpreter.restoreContextClassLoader(AbstractSparkInterpreter.scala:340)
org.apache.livy.repl.SparkInterpreter.start(SparkInterpreter.scala:63)
org.apache.livy.repl.Session.$anonfun$start$1(Session.scala:128)
scala.concurrent.Future$.$anonfun$apply$1(Future.scala:659)
scala.util.Success.$anonfun$map$1(Try.scala:255)
scala.util.Success.map(Try.scala:213)
scala.concurrent.Future.$anonfun$map$1(Future.scala:292)
scala.concurrent.impl.Promise.liftedTree1$1(Promise.scala:33)
scala.concurrent.impl.Promise.$anonfun$transform$1(Promise.scala:33)
scala.concurrent.impl.CallbackRunnable.run(Promise.scala:64)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
java.lang.Thread.run(Thread.java:748)
	at org.apache.spark.SparkContext$.$anonfun$assertNoOtherContextIsRunning$2(SparkContext.scala:2672)
	at scala.Option.foreach(Option.scala:407)
	at org.apache.spark.SparkContext$.assertNoOtherContextIsRunning(SparkContext.scala:2669)
	at org.apache.spark.SparkContext$.markPartiallyConstructed(SparkContext.scala:2759)
	at org.apache.spark.SparkContext.<init>(SparkContext.scala:96)
	at is.hail.backend.spark.SparkBackend$.configureAndCreateSparkContext(SparkBackend.scala:146)
	at is.hail.backend.spark.SparkBackend$.apply(SparkBackend.scala:222)
	at is.hail.backend.spark.SparkBackend.apply(SparkBackend.scala)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:244)
	at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:357)
	at py4j.Gateway.invoke(Gateway.java:282)
	at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:132)
	at py4j.commands.CallCommand.execute(CallCommand.java:79)
	at py4j.GatewayConnection.run(GatewayConnection.java:238)
	at java.lang.Thread.run(Thread.java:748)