spark.sparkContext.textFile(...) is not working

When using spark-3.1.2 with hadoop 3.2.0 spark.sparkContext.textFile(..) throws a NPE:

 
java.lang.NullPointerException
at org.apache.hadoop.mapred.TextInputFormat.isSplitable(TextInputFormat.java:49)
at org.apache.hadoop.mapred.FileInputFormat.getSplits(FileInputFormat.java:363)
at org.apache.spark.rdd.HadoopRDD.getPartitions(HadoopRDD.scala:205)
at org.apache.spark.rdd.RDD.$anonfun$partitions$2(RDD.scala:300)
at scala.Option.getOrElse(Option.scala:189)
at org.apache.spark.rdd.RDD.partitions(RDD.scala:296)
at org.apache.spark.rdd.MapPartitionsRDD.getPartitions(MapPartitionsRDD.scala:49)
at org.apache.spark.rdd.RDD.$anonfun$partitions$2(RDD.scala:300)
at scala.Option.getOrElse(Option.scala:189)
at org.apache.spark.rdd.RDD.partitions(RDD.scala:296)
at org.apache.spark.SparkContext.runJob(SparkContext.scala:2261)
at org.apache.spark.rdd.RDD.count(RDD.scala:1253)
... 114 elided
 

Built zepplein from master branch via
mvn clean package -DskipTests -Dcheckstyle.skip -Pbuild-distr -Pspark-3.1 -Phadoop3 -Pspark-scala-2.12 -Pscala-2.12 -Pinclude-hadoop -Pweb-dist
 

This works on spark-shell (spark-3.1.2 w/ hadoop 3.2.0) but not on zeppelins spark interpreter. 

This is blocking us from using spark 3.1.2 in production.