Traceback (most recent call last):
  File "rednotebook/journal.py", line 44, in <module>
    gi.require_version('GtkSource', '3.0')
  File "/gnu/store/zgq6zx6riin708xcl31xwz1ca786wr85-profile/lib/python3.7/site-packages/gi/__init__.py", line 134, in require_version
    (namespace, version))
ValueError: Namespace GtkSource not available for version 3.0