'You are using relations.html in html_sidebars. This configuration does not work with Shibuya ..."

[InSync]

There's this warning on the sidebar:

The link leads to nowhere (reported upstream). It seems that the correct manual page is this one, but even that doesn't mention anything about relations.html.

This is, perhaps, a problem with the following lines in docs/conf.py:

marko/docs/conf.py

Lines 104 to 111 in 5f784a4

 html_sidebars = { 
     "*": [ 
         "sidebarintro.html", 
         "localtoc.html", 
         "relations.html", 
         "sourcelink.html", 
     ] 
 } 

A potential fix is to remove the third element:

 html_sidebars = {
     "*": [
         "sidebarintro.html",
         "localtoc.html",
-        "relations.html",
         "sourcelink.html",
     ]
 }