geckodriver trace logs

[violinner]

Is there a flag or environment variable that will enable geckodriver to write trace logs when invoked by SeleniumWebDriver.startDriverFor("firefox")
?

[fhoeben]

I have to admit I don't know. I don't use Firefox much and never had a need for tracing.
This seems like the kind of thing that could be achieved by passing a particular profile parameter when starting. Your question suggests that is not what you are looking for, is that indeed the case?