Добрый день.

caffeine 
/usr/lib/python3/site-packages/caffeine/inhibitors.py:174: SyntaxWarning: "is" with a literal. Did you mean "=="?
  return os.system("pgrep xscreensaver") is 0
/usr/lib/python3/site-packages/caffeine/inhibitors.py:240: SyntaxWarning: "is" with a literal. Did you mean "=="?
  return os.system("pgrep xautolock") is 0
/usr/lib/python3/site-packages/caffeine/main.py:59: PyGIWarning: AppIndicator3 was imported without specifying a version first. Use gi.require_version('AppIndicator3', '0.1') before import to ensure that the right version gets loaded.
  from gi.repository import AppIndicator3

(caffeine:411008): Gtk-CRITICAL **: 15:35:20.208: gtk_icon_theme_get_for_screen: assertion 'GDK_IS_SCREEN (screen)' failed
Traceback (most recent call last):
  File "/usr/bin/caffeine", line 11, in <module>
    load_entry_point('caffeine-ng==3.4.2', 'gui_scripts', 'caffeine')()
  File "/usr/lib64/python3/site-packages/pkg_resources/__init__.py", line 474, in load_entry_point
    return get_distribution(dist).load_entry_point(group, name)
  File "/usr/lib64/python3/site-packages/pkg_resources/__init__.py", line 2846, in load_entry_point
    return ep.load()
  File "/usr/lib64/python3/site-packages/pkg_resources/__init__.py", line 2450, in load
    return self.resolve()
  File "/usr/lib64/python3/site-packages/pkg_resources/__init__.py", line 2456, in resolve
    module = __import__(self.module_name, fromlist=['__name__'], level=0)
  File "/usr/lib/python3/site-packages/caffeine/main.py", line 67, in <module>
    generic = icon_theme.load_icon("application-x-executable", 16,
AttributeError: 'NoneType' object has no attribute 'load_icon'