Bug report

Bug summary

This is not really a bug, but when I install a package (nexpy/nexpy) in Miniconda that uses Matplotlib, I get a deprecation warning about the use of the old qt_editor.formlayout module, which says that it will be removed in v3.3. The problem is that the replacement module cannot be listed as a dependency in conda because it is not available in either the default conda channel or Conda-forge. How will Matplotlib handle this dependency when 3.3 is released?

Code for reproduction

$ conda config --add channels conda-forge
$ conda install nexpy
$ conda install qtconsole
$ nexpy &

Actual outcome

This gives the following warning.

/home/rosborn/miniconda3/lib/python3.7/site-packages/nexpy/gui/widgets.py:21: MatplotlibDeprecationWarning: 
The matplotlib.backends.qt_editor.formlayout module was deprecated in Matplotlib 3.1 and will be removed in 3.3. Use the formlayout module available on PyPI instead.
  from matplotlib.backends.qt_editor.formlayout import (ColorLayout,

Matplotlib version

• Operating system:
• Matplotlib version: 3.1.1
• Matplotlib backend: Qt5Agg
• Python version: 3.7