Logs caught with OutputDirectoryLogging.catchLogEntries() are empty

[markusstraub]

Catching log statements with OutputDirectoryLogging.catchLogEntries() does not work with MATSim 2024.0 or 2025.0-SNAPSHOT.

Each log statement before logging is regularly initialized by the controller looks like this:

2024-10-30T09:13:26,415   OFF ?: 
2024-10-30T09:13:26,415   OFF ?: 
2024-10-30T09:13:26,415   OFF ?: 

I debugged a little bit:

• during early logs you can watch the list of logEvents (with instances of MutableLogEvent) in CollectLogMessagesAppender grow - and the events in the list contain valid log entries
• but when it's time to write them to the log (i.e. when OutputDirectoryLogging.initLogging is called from the controller) the length of the logEvents list seems to be OK but it only contains references to the same event with all fields set to null

But I have no clue where the log events are razed :/

How to reproduce: Run https://github.com/matsim-org/matsim-code-examples/blob/2024.x/src/main/java/org/matsim/codeexamples/events/eventsHandling/RunEventsHandlingWithControlerExample.java and have a look at logfile.log

[rakow]

Could it be that you are affected by issue #2318? Are you running matsim from an IDE or an executable jar ?

[markusstraub]

I was running it from an IDE. Maybe you could try to reproduce it by running the example as well? So that we know it's not my setup.

[rakow]

Yes, I can reproduce the same issue.