Explicitely set language to 'en'

doc/src/conf.py

@@ -46,10 +46,7 @@
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['_templates']
 
-# The suffix(es) of source filenames.
-# You can specify multiple suffix as a list of string:
-#
-# source_suffix = ['.rst', '.md']
+# The suffix of source filenames.
 source_suffix = '.rst'
 
 # The master toctree document.
@@ -60,7 +57,7 @@
 #
 # This is also used if you do content translation via gettext catalogs.
 # Usually you set "language" from the command line for these cases.
-language = None
+language = 'en'
 
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.
@@ -75,15 +72,13 @@
 
 autodoc_member_order = 'bysource'
 
-
 # -- Options for intersphinx extension ---------------------------------------
 
 intersphinx_mapping = {
     'python': ('https://docs.python.org/3', None),
     'pytest': ('https://docs.pytest.org/en/stable/', None),
 }
 
-
 # -- Options for HTML output -------------------------------------------------
 
 # The theme to use for HTML and HTML Help pages.  See the documentation for