Failed to recognize scikit-learn in qgis 3.10.7 on Gentoo

[UlvHare]

Params:

$ uname -a
Linux ipee251 4.9.228-gentoo-x86_64-Shu #1 SMP PREEMPT Fri Jun 26 12:15:46 MSK 2020 x86_64 Intel(R) Core(TM) i5-3450 CPU @ 3.10GHz GenuineIntel GNU/Linux
$ eselect python list
Available Python interpreters, in order of preference:
  [1]   python3.7
  [2]   python2.7
  [3]   python3.8 (fallback)
$ eix -I learn
[I] sci-libs/scikits_learn
     Available:      ~0.19.0-r1^t ~0.20.2^t ~0.20.4^t 0.22.2_p1^t {examples test PYTHON_TARGETS="python3_6 python3_7 python3_8"}
     Installed:  0.22.2_p1^t(15:26:24 15.07.2020)(-examples -test PYTHON_TARGETS="python3_7 -python3_6 -python3_8")

The library scikit-learn is installed. Python by itself recognized it: when I tried to install scikit-learn via pip it warned me that '...already installed'. No error/warning messages in QGIS.

I'm absolutely nub in Python, so was stuck for a day. But then I simply copypasted line

dzetsaka/dzetsaka.py

Line 881 in 7929567

from sklearn import metrics

to Python console and saw several errors ending with:

ModuleNotFoundError: no module named 'joblib'

And yes, dev-python/joblib wasn't installed! Installation of it and restarting QGIS allowed me to select Random Forest and others.

So it is not a real bug, but it will be nice just to write in README/greeting/etc about that requirement.