Normal Description
This is a followup ticket for CASSANDRA-10581. The consensus on the Cassandra TE is that the debug output for loading JEMAlloc is helpful (or at least harmless when starting C*, but not when starting nodetool, which, it turns out, sources cassandra-env:
https://github.com/apache/cassandra/blob/trunk/bin/nodetool#L53
You can reproduce the excessive output with
ccm create test-nodetool-output -v git:cassandra-3.0 -n 1 ; ccm start --wait-for-binary-proto ; ccm node1 nodetool ring
The simplest solution would probably be to redirect the output of the sourcing to /dev/null/. I don't know if that's the right thing to do; it may be better to move the LD_PRELOAD-setting logic to bin/cassandra. I'm not sure what the reasoning would be for putting something in one place or another, so I leave it to the dev team to decide on the best solution.
Assigning snazy for now; feel free to reassign