If it might help anyone else, I had a similar issue when running my unit tests, I could solve it by increasing memory of sbt
export SBT_OPTS="-Xmx3G -XX:+UseConcMarkSweepGC -XX:+CMSClassUnloadingEnabled -Xss1G" -- Sent from: http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/