Summary

Category-specific log levels configured via LLAMA_STACK_LOGGING environment variable are not applied to loggers that are created before setup_logging() is called.

Impact

When debugging specific categories (e.g., core=debug), log messages from modules imported early in the initialization process don't respect the configured log level and remain at the default level.

Reproduction Steps

1. Set the environment variable:

export LLAMA_STACK_LOGGING=core=debug

2. Start the llama-stack server

3. Observe that the DEBUG level log message from src/llama_stack/core/stack.py:488 is not displayed:

logger.debug("refreshing registry")

Expected Behavior

All loggers with category="core" should log at DEBUG level when LLAMA_STACK_LOGGING=core=debug is set, regardless of when the logger was initialized.

Actual Behavior

Loggers created before setup_logging() is called (e.g., in stack.py imported at server startup) do not respect category-specific log levels and remain at the default log level.

Root Cause

Loggers are created via get_logger() at module import time before setup_logging() is called. The existing implementation in setup_logging() only applies the root level to pre-existing llama_stack loggers, ignoring their individual category assignments stored in _category_levels.