Intended way to get DEBUG logging?

[kannes]

I cannot figure out how to get DEBUG logging messages to appear with this. I have not traced a message through all the code so sorry if below is stupid:

Logging is set up following https://github.com/GispoCoding/qgis_plugin_tools/blob/main/docs/usage.md#logging

A LOGGER.debug('Log some debug messages') just goes into the void. I am looking at stdout/stderr and the QGIS message log. The docs made me expect that debug messages would be handled in a "visible" way.

I see that the plugin has some logic around logging levels where DEBUG is turned into QGIS' INFO level (as QGIS has no DEBUG level). That seems to work fine by itself. Yet the messages do not appear in the QGIS message log.

In

qgis_plugin_tools/tools/custom_logging.py

Lines 26 to 31 in fd8650d

	class LogTarget(Enum):
	"""Log target with default logging level as value"""
	STREAM = {"id": "stream", "default": "INFO"}
	FILE = {"id": "file", "default": "INFO"}
	BAR = {"id": "bar", "default": "INFO"}

there are three handlers defined, all with INFO as level. Their levels are used in other places to set the minimum common level. So just looking at that, it makes sense that DEBUG messages are not logged. But I thought they would be turned into INFO level automagically somewhere?

I tried LOGGER.setLevel(logging.DEBUG) with no luck.

I tried setting all the handlers levels to DEBUG, this made them appear as DEBUG logs in the terminal and INFO logs in QGIS. How can I achieve that without modifying the code of this module?

[kannes]

I will dive deeper into this today and maybe try to add a logging_level parameter to setup_logger if that makes sense.

[kannes]

• There is some code that tries to load settings from QGIS3.ini (but it is currently broken: get_log_level_name() fetches wrong key from QgsSettings #84) so this should set up custom log levels per handler:

[MyPlugin]
log_level\bar=WARNING
log_level\file=CRITICAL
log_level\stream=DEBUG

This took quite a bit of time and then it made me give up trying to think of a reasonable way to integrate in the tools, and go for a quick fix for just my plugin instead:

I went with external overriding in my plugin's __init__.py (as early as possible to avoid confusion if imported modules do stuff with logging during import):

LOGGER = setup_logger(__name__.split(".")[0])

# Initially set DEBUG logging
LOGGER.setLevel(logging.DEBUG)
for handler in LOGGER.handlers:
    handler.setLevel(logging.DEBUG)

# read wanted logging level from somewhere (during which I might want DEBUG logging)
logging_level = ...  

# set the wanted logging level
LOGGER.setLevel(logging_level)
for handler in LOGGER.handlers:
    handler.setLevel(logging_level)

That way I can use LOGGER = logging.getLogger(__name__) anywhere else and have it use the correct level.

[kannes]

Warning, weird footgun! Due to reasons I switched to using the same logger everywhere via:

setup_logger(plugin_name()) and LOGGER = logging.getLogger(plugin_name())

Don't ask me why, but now I could not use the logger object returned by setup_logger anymore to set the logging level. It turned out to be a different logger:

>>> LOGGER = setup_logger(plugin_name())
>>> print(f"{id(LOGGER)=}")
id(LOGGER)=139887092455936
>>> LOGGER = logging.getLogger(plugin_name())
>>> print(f"{id(LOGGER)=}")
id(LOGGER)=139887097284736

Changing the level of the logger returned by setup_logger(plugin_name()) did nothing for the logger I used everywhere else via logging.getLogger(plugin_name()) D:

Instead I went with:

setup_logger(plugin_name())
LOGGER = logging.getLogger(plugin_name())
...  # as above