[🐛 Bug]: Hub fails to start with --log-level DEBUG

[ortunom]

Description

Environment:

• Selenium version: 4.33.0
• Java version: OpenJDK 17
• OS: macOS (Sonoma)

Steps to reproduce:

• java -jar selenium-server-4.33.0.jar hub --log-level DEBUG

Expected Result:

• Hub starts and logs appear at DEBUG level.

Actual Result:

• No output is shown.
• Hub process silently fails (no logs, no errors).
• Confirmed that --log /dev/stdout and -verbose show class loading but no actual boot logic.

Workarounds

• --log-level INFO works
• --log-level FINE works

I've tried older versions up to 4.15, none of them work with --log-level DEBUG, however there's a log message appearing with 4.15 - the log does not appear with any other version between 4.33 and 4.15:

java.lang.reflect.InvocationTargetException
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at org.openqa.selenium.grid.Bootstrap.runMain(Bootstrap.java:77)
	at org.openqa.selenium.grid.Bootstrap.main(Bootstrap.java:70)
Caused by: org.openqa.selenium.grid.config.ConfigException: Unable to determine log level from DEBUG
	at org.openqa.selenium.grid.log.LoggingOptions.setLoggingLevel(LoggingOptions.java:79)
	at org.openqa.selenium.grid.log.LoggingOptions.configureLogging(LoggingOptions.java:115)
	at org.openqa.selenium.grid.TemplateGridCommand.lambda$configure$4(TemplateGridCommand.java:120)
	at org.openqa.selenium.grid.Main.launch(Main.java:83)
	at org.openqa.selenium.grid.Main.go(Main.java:56)
	at org.openqa.selenium.grid.Main.main(Main.java:41)
	... 6 more

Reproducible Code

java -jar selenium-server-4.33.0.jar hub --log-level DEBUG

Debugging Logs

No logs at all.

[selenium-ci]

@ortunom, thank you for creating this issue. We will troubleshoot it as soon as we can.

Selenium Triage Team: remember to follow the Triage Guide

[VietND96]

Please read https://www.selenium.dev/documentation/grid/configuration/cli_options/#logging
DEBUG is not a support value

[nvborisenko]

@VietND96 then raise good exception what is supported.

[cgoldberg]

then raise good exception what is supported.

FWIW, pretty much none of the grid server args have proper validation and fail with a useful message. This would make a good bug/feature request with a "help wanted" tag to fix them all.

[ortunom]

Please read https://www.selenium.dev/documentation/grid/configuration/cli_options/#logging DEBUG is not a support value

OMG, I think I was reading debug levels for JavaScript rather than Java in the documentation 🤦