Fix get_html_theme_path warning

Author: relic-se

docs/conf.py

@@ -108,10 +108,18 @@
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
 #
-import sphinx_rtd_theme
-
-html_theme = "sphinx_rtd_theme"
-html_theme_path = [sphinx_rtd_theme.get_html_theme_path(), "."]
+on_rtd = os.environ.get('READTHEDOCS', None) == 'True'
+
+if not on_rtd:  # only import and set the theme if we're building docs locally
+    try:
+        import sphinx_rtd_theme
+        html_theme = 'sphinx_rtd_theme'
+        html_theme_path = [sphinx_rtd_theme.get_html_theme_path(), '.']
+    except:
+        html_theme = 'default'
+        html_theme_path = ['.']
+else:
+    html_theme_path = ['.']
 
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,