Visual Studio Code LSP extension hides traceback when test library throws an exception

How do I configure the Visual Studio code extension “Robot Framework Language Server” to output tracebacks when a custom Python test library keyword fails?

Normally if I were running from the command line, I could just do robot --loglevel DEBUG:DEBUG foo.robot and then I could just look at the log. But if I set this argument in VS Code’s launch.json, nothing happens, because it’s setup to launch the language server, like this (copy-and-pasted from the terminal window inside VS Code):

PS C:\foo\tests>  c:; cd 'c:\foo\tests'; & 'C:\Users\foo\AppData\Local\Temp\rf-ls-run\run_env_00_7_d9ve6l.bat' '-u' 'c:\Users\foo\.vscode\extensions\robocorp.robotframework-lsp-1.11.0\src\robotframework_debug_adapter\' '--port' '61005' '--no-debug' '--listener=robotframework_debug_adapter.events_listener.EventsListenerV2' '--listener=robotframework_debug_adapter.events_listener.EventsListenerV3' '--prerunmodifier=robotframework_debug_adapter.prerun_modifiers.FilteringTestsSuiteVisitor' 'c:\foo\tests\foo.robot' 

So how do I configure the VS Code extension to output with loglevel=DEBUG? Debugging with the debugger doesn’t do it. I can’t find any settings that do it. I googled, but found nothing.