Jmeter logs are missing - groovy

Question

I am not able to see log messages in the logger view and not in jmeter.log. I am writing a simple jmeter groovy script [jsr223 listener].
org.apache.jorphan.logging.LoggingManager;
private static final Logger log = LoggingManager.getLoggerForClass();
log.info("your log message");
log.error("your error message");
println("something");
System.Out.Println("other thing");
Logs
2021-01-19 01:23:28,999 INFO o.a.j.e.StandardJMeterEngine: Running the test!
2021-01-19 01:23:29,015 INFO o.a.j.s.SampleEvent: List of sample_variables: []
2021-01-19 01:23:29,015 INFO o.a.j.g.u.JMeterMenuBar: setRunning(true, *local*)
2021-01-19 01:23:29,050 INFO o.a.j.e.StandardJMeterEngine: Starting ThreadGroup: 1 : Thread Group
2021-01-19 01:23:29,050 INFO o.a.j.e.StandardJMeterEngine: Starting 1 threads for group Thread Group.
2021-01-19 01:23:29,050 INFO o.a.j.e.StandardJMeterEngine: Thread will continue on error
2021-01-19 01:23:29,066 INFO o.a.j.t.ThreadGroup: Starting thread group... number=1 threads=1 ramp-up=1 delayedStart=false
2021-01-19 01:23:29,066 INFO o.a.j.t.ThreadGroup: Started thread group number 1
2021-01-19 01:23:29,066 INFO o.a.j.e.StandardJMeterEngine: All thread groups have been started
2021-01-19 01:23:29,066 INFO o.a.j.t.JMeterThread: Thread started: Thread Group 1-1
2021-01-19 01:23:29,066 INFO o.a.j.t.JMeterThread: Thread is done: Thread Group 1-1
2021-01-19 01:23:29,066 INFO o.a.j.t.JMeterThread: Thread finished: Thread Group 1-1
2021-01-19 01:23:29,066 INFO o.a.j.e.StandardJMeterEngine: Notifying test listeners of end of test
2021-01-19 01:23:29,066 INFO o.a.j.g.u.JMeterMenuBar: setRunning(false, *local*)
Expecting to see log and error message atleast but none come through. Also , I tried jmeter 5.4.1 snapshot and same behavior. I am window OS / jmeter 5.4 . Can clue what I might be missing?

Answer 1

You don't need the two first lines, log is a pre-defined variable for the JSR223 Test Elements, see Top 8 JMeter Java Classes You Should Be Using with Groovy article for more details.
The last line should look like System.out.println("other thing");
The last two lines print stuff not into the log file but to STDOUT
You should see an error message, something like unable to resolve class Logger, if you don't see it - your listener is not being executed at all