No info after setting the QT_LOGGING_DEBUG env var

According to docs for QLoggingCategory:

Set the QT_LOGGING_DEBUG environment variable to find out where your logging rules are loaded from.

So, after doing:

QT_LOGGING_DEBUG=1 ./bin/qtcreator

I would expect some printout with the info about where my logging rules are loaded from. But I see no output.

Additional info: is seems that qtLoggingDebug() from qloggingregistry.cpp isn't hit at all, even after Creator has already printed something for some log category.