Critical Description
I noticed that https://repository.apache.org/content/groups/snapshots/org/apache/spark/spark-sql_2.11/2.4.0-SNAPSHOT/spark-sql_2.11-2.4.0-20180803.100335-189.pom does not exclude the normal version of orc-core. Comparing with https://github.com/apache/spark/blob/92b48842b944a3e430472294cdc3c481bad6b804/sql/core/pom.xml#L108 and https://github.com/apache/spark/blob/92b48842b944a3e430472294cdc3c481bad6b804/pom.xml#L1767, we only exclude the normal version of orc-core in the parent pom. So, the problem is that if a developer depends on spark-sql-core directly, orc-core and orc-core-nohive will be in the dependency list.
