From #814 (comment)

Dear all, sorry to reopen this thread, but I'm quite sure this MR breaks the Jupyter-Book compilation. The error message is the following one:

Extension error (sphinx_book_theme):
Handler <function update_general_config at 0x7f09a7474790> for event 'config-inited' threw an exception (exception: update_general_config() takes 1 positional argument but 2 were given)
Traceback (most recent call last):
  File "/home/user/.local/lib/python3.9/site-packages/sphinx/events.py", line 97, in emit
    results.append(listener.handler(self.app, *args))
TypeError: update_general_config() takes 1 positional argument but 2 were given

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/home/user/.local/lib/python3.9/site-packages/jupyter_book/sphinx.py", line 114, in build_sphinx
    app = Sphinx(
  File "/home/user/.local/lib/python3.9/site-packages/sphinx/application.py", line 257, in __init__
    self.events.emit('config-inited', self.config)
  File "/home/user/.local/lib/python3.9/site-packages/sphinx/events.py", line 108, in emit
    raise ExtensionError(__("Handler %r for event %r threw an exception") %
sphinx.errors.ExtensionError: Handler <function update_general_config at 0x7f09a7474790> for event 'config-inited' threw an exception (exception: update_general_config() takes 1 positional argument but 2 were given)

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/home/user/.local/bin/jupyter-book", line 8, in <module>
    sys.exit(main())
  File "/home/user/.local/lib/python3.9/site-packages/click/core.py", line 1130, in __call__
    return self.main(*args, **kwargs)
  File "/home/user/.local/lib/python3.9/site-packages/click/core.py", line 1055, in main
    rv = self.invoke(ctx)
  File "/home/user/.local/lib/python3.9/site-packages/click/core.py", line 1657, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/home/user/.local/lib/python3.9/site-packages/click/core.py", line 1404, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/home/user/.local/lib/python3.9/site-packages/click/core.py", line 760, in invoke
    return __callback(*args, **kwargs)
  File "/home/user/.local/lib/python3.9/site-packages/jupyter_book/cli/main.py", line 317, in build
    builder_specific_actions(
  File "/home/user/.local/lib/python3.9/site-packages/jupyter_book/cli/main.py", line 528, in builder_specific_actions
    raise RuntimeError(_message_box(msg, color="red", doprint=False)) from result
RuntimeError: 
===============================================================================

There was an error in building your book. Look above for the cause.

===============================================================================

Steps to reproduce:

• Install Jupyter Book: pip install jupyter-book
• Quickly generate a sample book: jupyter-book create mynewbook/
• Build the sample book: jupyter-book build mynewbook/

No issues found when reverting to 1.1.0 version. Thanks in advance and apologies if the culprit is not here!

Originally posted by @frgigr in #814 (comment)