Typed Schema package hack doesn't work with sbt

[marmbrus]

java.lang.IllegalAccessError: tried to access method org.apache.avro.Schema.(Lorg/apache/avro/Schema$Type;)V from class org.apache.avro.TypedSchema
at org.apache.avro.TypedSchema.(TypedSchema.scala:9)
at edu.berkeley.cs.avro.runtime.package$.genericContainerSchema(package.scala:9)
at edu.berkeley.cs.scads.piql.modeling.FileTraceSink.(FileTraceSink.scala:19)
at edu.berkeley.cs.scads.piql.modeling.TracingExample$.main(TracingExample.scala:20)
at edu.berkeley.cs.scads.piql.modeling.TracingExample.main(TracingExample.scala)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at sbt.Run.invokeMain(Run.scala:69)
at sbt.Run.run0(Run.scala:60)
at sbt.Run.execute$1(Run.scala:48)
at sbt.Run$$anonfun$run$2.apply(Run.scala:51)
at sbt.Run$$anonfun$run$2.apply(Run.scala:51)
at sbt.TrapExit$.executeMain$1(TrapExit.scala:33)
at sbt.TrapExit$$anon$1.run(TrapExit.scala:42)