org.apache.cassandra.utils.concurrent.Ref$State@6b25a2cc) to class org.apache.cassandra.io.sstable.format.SSTableReader$InstanceTidier@1601791084:/Users/atolbert/Documents/Projects/sstable-tools/ma-1-big was not released before the reference was garbage collected.
Seems to happen for each SSTable opened, but only with mvn exec:java. I can't seem to reproduce using an executable jar.