Jupyter-book: max() arg is an empty sequence error in building book

[luukalt]

When I try to build the demo book with:

_jupyter-book create newbook/_

And then build the book by:

_jupyter-book build newbook_

I receive the following output and error in the anaconda cmd window:

(wintest) C:\Users\laaltenburg>jupyter-book build newbook
Running Jupyter-Book v0.8.3
Traceback (most recent call last):
  File "c:\users\laaltenburg\.conda\envs\wintest\lib\runpy.py", line 193, in _run_module_as_main
    "__main__", mod_spec)
  File "c:\users\laaltenburg\.conda\envs\wintest\lib\runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "C:\Users\laaltenburg\.conda\envs\wintest\Scripts\jupyter-book.exe\__main__.py", line 7, in <module>
  File "c:\users\laaltenburg\.conda\envs\wintest\lib\site-packages\click\core.py", line 829, in __call__
    return self.main(*args, **kwargs)
  File "c:\users\laaltenburg\.conda\envs\wintest\lib\site-packages\click\core.py", line 782, in main
    rv = self.invoke(ctx)
  File "c:\users\laaltenburg\.conda\envs\wintest\lib\site-packages\click\core.py", line 1259, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "c:\users\laaltenburg\.conda\envs\wintest\lib\site-packages\click\core.py", line 1066, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "c:\users\laaltenburg\.conda\envs\wintest\lib\site-packages\click\core.py", line 610, in invoke
    return callback(*args, **kwargs)
  File "c:\users\laaltenburg\.conda\envs\wintest\lib\site-packages\jupyter_book\commands\__init__.py", line 199, in build
    build_modified = max([os.stat(ii).st_mtime for ii in build_files])
ValueError: max() arg is an empty sequence_

Something apparently is going wrong during the build, what could be the issue?

Thanks,
Luuk

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[Dedalo01]

I get the same error everytime too:

C:\Users\gaem1\Documents\JUPYTERBOOKS\provaJB>jb build example 
Running Jupyter-Book v0.8.3 
Traceback (most recent call last): 
File "c:\python39\lib\runpy.py", line 197, in _run_module_as_main 
return _run_code(code, main_globals, None, 
File "c:\python39\lib\runpy.py", line 87, in _run_code 
exec(code, run_globals) 
File "C:\Python39\Scripts\jb.exe\__main__.py", line 7, in <module> 
File "c:\python39\lib\site-packages\click\core.py", line 829, in __call__ 
return self.main(*args, **kwargs) 
File "c:\python39\lib\site-packages\click\core.py", line 782, in main 
rv = self.invoke(ctx) 
File "c:\python39\lib\site-packages\click\core.py", line 1259, in invoke 
return _process_result(sub_ctx.command.invoke(sub_ctx)) 
File "c:\python39\lib\site-packages\click\core.py", line 1066, in invoke 
return ctx.invoke(self.callback, **ctx.params) 
File "c:\python39\lib\site-packages\click\core.py", line 610, in invoke 
return callback(*args, **kwargs) 
File "c:\python39\lib\site-packages\jupyter_book\commands\__init__.py", line 199, in build 
build_modified = max([os.stat(ii).st_mtime for ii in build_files]) 
ValueError: max() arg is an empty sequence

I'm on Windows10 and I tried even on Ubuntu 20.4 (Using virtualBox on the same laptop)

[luukalt]

Any idea what possibly could be the case?

[fcharih]

Issue seems to be there:
https://github.com/executablebooks/jupyter-book/blob/9794ae55619288b8ada0e365c8a9d987968a44a5/jupyter_book/commands/__init__.py#L234

I just commented the line and set freshenv to True to automatically force a TOC rebuild.

[Dedalo01]

Issue seems to be there:
https://github.com/executablebooks/jupyter-book/blob/9794ae55619288b8ada0e365c8a9d987968a44a5/jupyter_book/commands/__init__.py#L234

I just commented the line and set freshenv to True to automatically force a TOC rebuild.

Ok I commented that line and set freshenv to True... now I get this error:

sphinx-err-zwh3_499.log

I'm trying to build the example book created with jupyter-build create example/
Could it be that I'm using python 3.9? (P.s: I'm a complete noob xD)

# Sphinx version: 3.3.1
# Python version: 3.9.0 (CPython)
# Docutils version: 0.16 release
# Jinja2 version: 2.11.2
# Last messages:
#   building [mo]: targets for 0 po files that are out of date
#   building [html]: targets for 4 source files that are out of date
#   updating environment:
#   [new config]
#   4 added, 0 changed, 0 removed
#   reading sources... [ 25%] content
#   reading sources... [ 50%] intro
#   reading sources... [ 75%] markdown
#   reading sources... [100%] notebooks
#   Executing: notebooks in: C:\Users\gaem1\Documents\JUPYTER BOOKS\provaJB\example
# Loaded extensions:
#   sphinx.ext.mathjax (3.3.1) from c:\python39\lib\site-packages\sphinx\ext\mathjax.py
#   sphinxcontrib.applehelp (1.0.2) from c:\python39\lib\site-packages\sphinxcontrib\applehelp\__init__.py
#   sphinxcontrib.devhelp (1.0.2) from c:\python39\lib\site-packages\sphinxcontrib\devhelp\__init__.py
#   sphinxcontrib.htmlhelp (1.0.3) from c:\python39\lib\site-packages\sphinxcontrib\htmlhelp\__init__.py
#   sphinxcontrib.serializinghtml (1.1.4) from c:\python39\lib\site-packages\sphinxcontrib\serializinghtml\__init__.py
#   sphinxcontrib.qthelp (1.0.3) from c:\python39\lib\site-packages\sphinxcontrib\qthelp\__init__.py
#   alabaster (0.7.12) from c:\python39\lib\site-packages\alabaster\__init__.py
#   sphinx_togglebutton (0.2.3) from c:\python39\lib\site-packages\sphinx_togglebutton\__init__.py
#   sphinx_copybutton (0.3.1) from c:\python39\lib\site-packages\sphinx_copybutton\__init__.py
#   myst_nb (0.10.1) from c:\python39\lib\site-packages\myst_nb\__init__.py
#   jupyter_book (0.8.3) from c:\python39\lib\site-packages\jupyter_book\__init__.py
#   sphinxcontrib.bibtex (unknown version) from c:\python39\lib\site-packages\sphinxcontrib\bibtex\__init__.py
#   sphinx_thebe (0.0.8) from c:\python39\lib\site-packages\sphinx_thebe\__init__.py
#   sphinx_comments (0.0.3) from c:\python39\lib\site-packages\sphinx_comments\__init__.py
#   sphinx.ext.intersphinx (3.3.1) from c:\python39\lib\site-packages\sphinx\ext\intersphinx.py
#   sphinx_panels (0.5.2) from c:\python39\lib\site-packages\sphinx_panels\__init__.py
#   sphinx_book_theme (unknown version) from c:\python39\lib\site-packages\sphinx_book_theme\__init__.py
#   pydata_sphinx_theme (unknown version) from c:\python39\lib\site-packages\pydata_sphinx_theme\__init__.py
Traceback (most recent call last):
  File "c:\python39\lib\site-packages\jupyter_book\sphinx.py", line 141, in build_sphinx
    app.build(force_all, filenames)
  File "c:\python39\lib\site-packages\sphinx\application.py", line 352, in build
    self.builder.build_update()
  File "c:\python39\lib\site-packages\sphinx\builders\__init__.py", line 297, in build_update
    self.build(to_build,
  File "c:\python39\lib\site-packages\sphinx\builders\__init__.py", line 311, in build
    updated_docnames = set(self.read())
  File "c:\python39\lib\site-packages\sphinx\builders\__init__.py", line 418, in read
    self._read_serial(docnames)
  File "c:\python39\lib\site-packages\sphinx\builders\__init__.py", line 439, in _read_serial
    self.read_doc(docname)
  File "c:\python39\lib\site-packages\sphinx\builders\__init__.py", line 479, in read_doc
    doctree = read_doc(self.app, self.env, self.env.doc2path(docname))
  File "c:\python39\lib\site-packages\sphinx\io.py", line 223, in read_doc
    pub.publish()
  File "c:\python39\lib\site-packages\docutils\core.py", line 217, in publish
    self.document = self.reader.read(self.source, self.parser,
  File "c:\python39\lib\site-packages\sphinx\io.py", line 128, in read
    self.parse()
  File "c:\python39\lib\site-packages\docutils\readers\__init__.py", line 77, in parse
    self.parser.parse(self.input, document)
  File "c:\python39\lib\site-packages\myst_nb\parser.py", line 75, in parse
    ntbk = generate_notebook_outputs(
  File "c:\python39\lib\site-packages\myst_nb\execution.py", line 138, in generate_notebook_outputs
    result = single_nb_execution(
  File "c:\python39\lib\site-packages\jupyter_cache\executors\utils.py", line 51, in single_nb_execution
    executenb(
  File "c:\python39\lib\site-packages\nbclient\client.py", line 1087, in execute
    return NotebookClient(nb=nb, resources=resources, km=km, **kwargs).execute()
  File "c:\python39\lib\site-packages\nbclient\util.py", line 74, in wrapped
    return just_run(coro(*args, **kwargs))
  File "c:\python39\lib\site-packages\nbclient\util.py", line 53, in just_run
    return loop.run_until_complete(coro)
  File "c:\python39\lib\asyncio\base_events.py", line 642, in run_until_complete
    return future.result()
  File "c:\python39\lib\site-packages\nbclient\client.py", line 524, in async_execute
    async with self.async_setup_kernel(**kwargs):
  File "c:\python39\lib\site-packages\async_generator\_util.py", line 34, in __aenter__
    return await self._agen.asend(None)
  File "c:\python39\lib\site-packages\nbclient\client.py", line 483, in async_setup_kernel
    await self.async_start_new_kernel_client()
  File "c:\python39\lib\site-packages\nbclient\client.py", line 408, in async_start_new_kernel_client
    await ensure_async(self.kc.start_channels())
  File "c:\python39\lib\site-packages\jupyter_client\client.py", line 106, in start_channels
    self.shell_channel.start()
  File "c:\python39\lib\site-packages\jupyter_client\client.py", line 151, in shell_channel
    socket = self.connect_shell(identity=self.session.bsession)
  File "c:\python39\lib\site-packages\jupyter_client\connect.py", line 561, in connect_shell
    return self._create_connected_socket('shell', identity=identity)
  File "c:\python39\lib\site-packages\jupyter_client\connect.py", line 545, in _create_connected_socket
    sock = self.context.socket(socket_type)
  File "c:\python39\lib\site-packages\zmq\sugar\context.py", line 226, in socket
    s = self._socket_class(self, socket_type, **kwargs)
  File "c:\python39\lib\site-packages\zmq\_future.py", line 144, in __init__
    self._init_io_state()
  File "c:\python39\lib\site-packages\zmq\asyncio.py", line 56, in _init_io_state
    self.io_loop.add_reader(self._fd, lambda: self._handle_events(0, 0))
  File "c:\python39\lib\asyncio\events.py", line 504, in add_reader
    raise NotImplementedError
NotImplementedError

Also tried with Anaconda (Python 3.7.9) and here I get a different error:
sphinx.errors.ExtensionError: You must configure the bibtex_bibfiles setting

C:\Users\gaem1\Documents\JUPYTER BOOKS\provaJB>jb build example
Running Jupyter-Book v0.8.3
Source Folder: C:\Users\gaem1\Documents\JUPYTER BOOKS\provaJB\example
Config Path: C:\Users\gaem1\Documents\JUPYTER BOOKS\provaJB\example\_config.yml
Output Path: C:\Users\gaem1\Documents\JUPYTER BOOKS\provaJB\example\_build\html
Running Sphinx v3.3.1
myst v0.12.10: MdParserConfig(renderer='sphinx', commonmark_only=False, dmath_enable=True, dmath_allow_labels=True, dmath_allow_space=True, dmath_allow_digits=True, amsmath_enable=False, deflist_enable=False, update_mathjax=True, admonition_enable=False, figure_enable=False, disable_syntax=[], html_img_enable=False, url_schemes=['mailto', 'http', 'https'], heading_anchors=None)

Extension error:
You must configure the bibtex_bibfiles setting
Traceback (most recent call last):
  File "c:\users\gaem1\anaconda3\envs\jupyter-book_py3_6\lib\site-packages\jupyter_book\sphinx.py", line 124, in build_sphinx
    keep_going=keep_going,
  File "c:\users\gaem1\anaconda3\envs\jupyter-book_py3_6\lib\site-packages\sphinx\application.py", line 278, in __init__
    self._init_builder()
  File "c:\users\gaem1\anaconda3\envs\jupyter-book_py3_6\lib\site-packages\sphinx\application.py", line 337, in _init_builder
    self.events.emit('builder-inited')
  File "c:\users\gaem1\anaconda3\envs\jupyter-book_py3_6\lib\site-packages\sphinx\events.py", line 110, in emit
    results.append(listener.handler(self.app, *args))
  File "c:\users\gaem1\anaconda3\envs\jupyter-book_py3_6\lib\site-packages\sphinxcontrib\bibtex\__init__.py", line 45, in init_bibtex_cache
    raise ExtensionError("You must configure the bibtex_bibfiles setting")
sphinx.errors.ExtensionError: You must configure the bibtex_bibfiles setting

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

Traceback (most recent call last):
  File "c:\users\gaem1\anaconda3\envs\jupyter-book_py3_6\lib\runpy.py", line 193, in _run_module_as_main
    "__main__", mod_spec)
  File "c:\users\gaem1\anaconda3\envs\jupyter-book_py3_6\lib\runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "C:\Users\gaem1\anaconda3\envs\jupyter-book_py3_6\Scripts\jb.exe\__main__.py", line 7, in <module>
  File "c:\users\gaem1\anaconda3\envs\jupyter-book_py3_6\lib\site-packages\click\core.py", line 829, in __call__
    return self.main(*args, **kwargs)
  File "c:\users\gaem1\anaconda3\envs\jupyter-book_py3_6\lib\site-packages\click\core.py", line 782, in main
    rv = self.invoke(ctx)
  File "c:\users\gaem1\anaconda3\envs\jupyter-book_py3_6\lib\site-packages\click\core.py", line 1259, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "c:\users\gaem1\anaconda3\envs\jupyter-book_py3_6\lib\site-packages\click\core.py", line 1066, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "c:\users\gaem1\anaconda3\envs\jupyter-book_py3_6\lib\site-packages\click\core.py", line 610, in invoke
    return callback(*args, **kwargs)
  File "c:\users\gaem1\anaconda3\envs\jupyter-book_py3_6\lib\site-packages\jupyter_book\commands\__init__.py", line 260, in build
    result, builder, OUTPUT_PATH, build_type, PAGE_NAME, click.echo
  File "c:\users\gaem1\anaconda3\envs\jupyter-book_py3_6\lib\site-packages\jupyter_book\commands\__init__.py", line 500, 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.

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


(jupyter-book_py3_6) C:\Users\gaem1\Documents\JUPYTER BOOKS\provaJB>

[choldgraf]

it's strange that this error is coming up on both linux and windows - it sounds like it isn't finding any build files which is why max is failing (can you confirm this is the case?)

the bibtex error is fixed by this one #1138

make sure sphinxcontrib-bibtex is pinned to 1.0 because 2.0 introduces some bugs that you're seeing here

[luukalt]

The directory does contain build files, since it is the demo book of the jupyter project itself.
Where does it look for build files?

I receive the exact same errors as @Dedalo01

[luukalt]

Pinning sphinxcontrib-bibtex to 1.0 does not solve the bibtex problem in my case (added sphinxcontrib-bibtex==1.0.0 to requirements.txt).

The other problem is:

File "c:\users\laaltenburg\.conda\envs\wintest3\lib\site-packages\jupyter_book\commands\__init__.py", line 500, in builder_specific_actions
    raise RuntimeError(_message_box(msg, color="red", doprint=False)) from result

Sorry for the hassle, I want to start creating and exploring as soon as possible, because I think the project in itself is amazing.

[Dedalo01]

Ok I can say that I finally DID IT!!!!!!!!!!!!!
(On my VirtualBox it's installed Python 3.8.5)

Issue seems to be there:
https://github.com/executablebooks/jupyter-book/blob/9794ae55619288b8ada0e365c8a9d987968a44a5/jupyter_book/commands/__init__.py#L234

I just commented the line and set freshenv to True to automatically force a TOC rebuild.

I did again this on my ubuntu 20.4 virtualBox and it worked!

gaetano@gaetano-VirtualBox:~/Documenti/JUPYTERBOOKS$ jb build example/
Running Jupyter-Book v0.8.3
Traceback (most recent call last):
  File "/home/gaetano/.local/bin/jb", line 8, in <module>
    sys.exit(main())
  File "/usr/lib/python3/dist-packages/click/core.py", line 764, in __call__
    return self.main(*args, **kwargs)
  File "/usr/lib/python3/dist-packages/click/core.py", line 717, in main
    rv = self.invoke(ctx)
  File "/usr/lib/python3/dist-packages/click/core.py", line 1137, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/usr/lib/python3/dist-packages/click/core.py", line 956, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/usr/lib/python3/dist-packages/click/core.py", line 555, in invoke
    return callback(*args, **kwargs)
  File "/home/gaetano/.local/lib/python3.8/site-packages/jupyter_book/commands/__init__.py", line 199, in build
    build_modified = max([os.stat(ii).st_mtime for ii in build_files])
ValueError: max() arg is an empty sequence

ABOVE WAS BEFORE FIXING THE CODE AS @fcharih SAID, BELOW IS AFTER I FIXED THE /__init__.py FILE:

gaetano@gaetano-VirtualBox:~/Documenti/JUPYTERBOOKS$ jb build example/
Running Jupyter-Book v0.8.3
Source Folder: /home/gaetano/Documenti/JUPYTERBOOKS/example
Config Path: /home/gaetano/Documenti/JUPYTERBOOKS/example/_config.yml
Output Path: /home/gaetano/Documenti/JUPYTERBOOKS/example/_build/html
Running Sphinx v3.3.1
myst v0.12.10: MdParserConfig(renderer='sphinx', commonmark_only=False, dmath_enable=True, dmath_allow_labels=True, dmath_allow_space=True, dmath_allow_digits=True, amsmath_enable=False, deflist_enable=False, update_mathjax=True, admonition_enable=False, figure_enable=False, disable_syntax=[], html_img_enable=False, url_schemes=['mailto', 'http', 'https'], heading_anchors=None)
building [mo]: targets for 0 po files that are out of date
building [html]: targets for 4 source files that are out of date
updating environment: [new config] 4 added, 0 changed, 0 removed
checking for /home/gaetano/Documenti/JUPYTERBOOKS/example/references.bib in bibtex cache... not found
parsing bibtex file /home/gaetano/Documenti/JUPYTERBOOKS/example/references.bib... parsed 5 entries
Executing: notebooks in: /home/gaetano/Documenti/JUPYTERBOOKS/example           

looking for now-outdated files... none found
pickling environment... done
checking consistency... done
preparing documents... done
writing output... [100%] notebooks                                              
generating indices... genindex done
writing additional pages... search done
copying images... [100%] _build/jupyter_execute/notebooks_2_0.png               
copying static files... done
copying extra files... done
dumping search index in English (code: en)... done
dumping object inventory... done
build succeeded.

The HTML pages are in example/_build/html.

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

Finished generating HTML for book.
Your book's HTML pages are here:
    example/_build/html/
You can look at your book by opening this file in a browser:
    example/_build/html/index.html
Or paste this line directly into your browser bar:
    file:///home/gaetano/Documenti/JUPYTERBOOKS/example/_build/html/index.html            

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

gaetano@gaetano-VirtualBox:~/Documenti/JUPYTERBOOKS$

I will try now to create a new Anaconda Enviroment with Anaconda Navigator, but this time I will install python 3.8.5 if I can...
@luukalt you can try as I did with Virtual Box and Linux!!!

[luukalt]

Nice! I seem to have trouble to create an environment with python 3.8.5.

Did you only change the /init.py file?
What did you do about the " sphinxcontrib-bibtex" or is this problem not present in Linux?

Any help is still appreciated!

[Dedalo01]

@luukalt I've just tried with Anaconda Python 3.8.5 :
First I launched the Anaconda terminal from Anaconda Navigator, then:

1. I installed jupyter book
2. I uninstalled sphinxcontrib-bibtex using pip uninstall sphinxcontrib-bibtex
3. I installed sphinxcontrib-bibtex-1.0.0 using pip install sphinxcontrib-bibtex==1.0.0
4. I created a new example using jb create esempio3

Now I get this error:

(JB_python3_8) C:\Users\gaem1\Documents\JUPYTER BOOKS>jb build esempio3
Running Jupyter-Book v0.8.3
Source Folder: C:\Users\gaem1\Documents\JUPYTER BOOKS\esempio3
Config Path: C:\Users\gaem1\Documents\JUPYTER BOOKS\esempio3\_config.yml
Output Path: C:\Users\gaem1\Documents\JUPYTER BOOKS\esempio3\_build\html
Running Sphinx v3.3.1
myst v0.12.10: MdParserConfig(renderer='sphinx', commonmark_only=False, dmath_enable=True, dmath_allow_labels=True, dmath_allow_space=True, dmath_allow_digits=True, amsmath_enable=False, deflist_enable=False, update_mathjax=True, admonition_enable=False, figure_enable=False, disable_syntax=[], html_img_enable=False, url_schemes=['mailto', 'http', 'https'], heading_anchors=None)
building [mo]: targets for 0 po files that are out of date
building [html]: targets for 4 source files that are out of date
updating environment: [new config] 4 added, 0 changed, 0 removed
checking for C:\Users\gaem1\Documents\JUPYTER BOOKS\esempio3\references.bib in bibtex cache... not found
parsing bibtex file C:\Users\gaem1\Documents\JUPYTER BOOKS\esempio3\references.bib... parsed 5 entries
Executing: notebooks in: C:\Users\gaem1\Documents\JUPYTER BOOKS\esempio3

Exception occurred:
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\asyncio\events.py", line 501, in add_reader
    raise NotImplementedError
NotImplementedError
The full traceback has been saved in C:\Users\gaem1\AppData\Local\Temp\sphinx-err-5r9xtbrz.log, if you want to report the issue to the developers.
Please also report this if it was a user error, so that a better error message can be provided next time.
A bug report can be filed in the tracker at <https://github.com/sphinx-doc/sphinx/issues>. Thanks!
Traceback (most recent call last):
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\jupyter_book\sphinx.py", line 141, in build_sphinx
    app.build(force_all, filenames)
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\sphinx\application.py", line 352, in build
    self.builder.build_update()
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\sphinx\builders\__init__.py", line 297, in build_update
    self.build(to_build,
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\sphinx\builders\__init__.py", line 311, in build
    updated_docnames = set(self.read())
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\sphinx\builders\__init__.py", line 418, in read
    self._read_serial(docnames)
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\sphinx\builders\__init__.py", line 439, in _read_serial
    self.read_doc(docname)
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\sphinx\builders\__init__.py", line 479, in read_doc
    doctree = read_doc(self.app, self.env, self.env.doc2path(docname))
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\sphinx\io.py", line 223, in read_doc
    pub.publish()
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\docutils\core.py", line 217, in publish
    self.document = self.reader.read(self.source, self.parser,
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\sphinx\io.py", line 128, in read
    self.parse()
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\docutils\readers\__init__.py", line 77, in parse
    self.parser.parse(self.input, document)
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\myst_nb\parser.py", line 75, in parse
    ntbk = generate_notebook_outputs(
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\myst_nb\execution.py", line 138, in generate_notebook_outputs
    result = single_nb_execution(
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\jupyter_cache\executors\utils.py", line 51, in single_nb_execution
    executenb(
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\nbclient\client.py", line 1087, in execute
    return NotebookClient(nb=nb, resources=resources, km=km, **kwargs).execute()
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\nbclient\util.py", line 74, in wrapped
    return just_run(coro(*args, **kwargs))
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\nbclient\util.py", line 53, in just_run
    return loop.run_until_complete(coro)
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\asyncio\base_events.py", line 616, in run_until_complete
    return future.result()
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\nbclient\client.py", line 524, in async_execute
    async with self.async_setup_kernel(**kwargs):
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\async_generator\_util.py", line 34, in __aenter__
    return await self._agen.asend(None)
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\nbclient\client.py", line 483, in async_setup_kernel
    await self.async_start_new_kernel_client()
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\nbclient\client.py", line 408, in async_start_new_kernel_client
    await ensure_async(self.kc.start_channels())
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\jupyter_client\client.py", line 106, in start_channels
    self.shell_channel.start()
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\jupyter_client\client.py", line 151, in shell_channel
    socket = self.connect_shell(identity=self.session.bsession)
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\jupyter_client\connect.py", line 561, in connect_shell
    return self._create_connected_socket('shell', identity=identity)
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\jupyter_client\connect.py", line 545, in _create_connected_socket
    sock = self.context.socket(socket_type)
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\zmq\sugar\context.py", line 226, in socket
    s = self._socket_class(self, socket_type, **kwargs)
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\zmq\_future.py", line 144, in __init__
    self._init_io_state()
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\zmq\asyncio.py", line 56, in _init_io_state
    self.io_loop.add_reader(self._fd, lambda: self._handle_events(0, 0))
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\asyncio\events.py", line 501, in add_reader
    raise NotImplementedError
NotImplementedError

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

Traceback (most recent call last):
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\runpy.py", line 194, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "C:\Users\gaem1\anaconda3\envs\JB_python3_8\Scripts\jb.exe\__main__.py", line 7, in <module>
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\click\core.py", line 829, in __call__
    return self.main(*args, **kwargs)
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\click\core.py", line 782, in main
    rv = self.invoke(ctx)
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\click\core.py", line 1259, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\click\core.py", line 1066, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\click\core.py", line 610, in invoke
    return callback(*args, **kwargs)
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\jupyter_book\commands\__init__.py", line 259, in build
    builder_specific_actions(
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\jupyter_book\commands\__init__.py", line 500, 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.

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

Error in atexit._run_exitfuncs:
Traceback (most recent call last):
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\nbclient\client.py", line 365, in _async_cleanup_kernel
    await ensure_async(self.kc.stop_channels())
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\jupyter_client\client.py", line 125, in stop_channels
    if self.shell_channel.is_alive():
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\jupyter_client\client.py", line 151, in shell_channel
    socket = self.connect_shell(identity=self.session.bsession)
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\jupyter_client\connect.py", line 561, in connect_shell
    return self._create_connected_socket('shell', identity=identity)
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\jupyter_client\connect.py", line 545, in _create_connected_socket
    sock = self.context.socket(socket_type)
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\zmq\sugar\context.py", line 226, in socket
    s = self._socket_class(self, socket_type, **kwargs)
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\zmq\_future.py", line 144, in __init__
    self._init_io_state()
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\zmq\asyncio.py", line 56, in _init_io_state
    self.io_loop.add_reader(self._fd, lambda: self._handle_events(0, 0))
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\asyncio\events.py", line 501, in add_reader
    raise NotImplementedError
NotImplementedError
Exception ignored in: <function Socket.__del__ at 0x00000237824DDB80>
Traceback (most recent call last):
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\zmq\sugar\socket.py", line 68, in __del__
    self.close()
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\zmq\_future.py", line 160, in close
    self._clear_io_state()
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\zmq\asyncio.py", line 63, in _clear_io_state
    self.io_loop.remove_reader(self._fd)
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\asyncio\events.py", line 504, in remove_reader
    raise NotImplementedError
NotImplementedError:
Exception ignored in: <function Socket.__del__ at 0x00000237824DDB80>
Traceback (most recent call last):
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\zmq\sugar\socket.py", line 68, in __del__
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\zmq\_future.py", line 160, in close
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\site-packages\zmq\asyncio.py", line 63, in _clear_io_state
  File "c:\users\gaem1\anaconda3\envs\jb_python3_8\lib\asyncio\events.py", line 504, in remove_reader
NotImplementedError:

(JB_python3_8) C:\Users\gaem1\Documents\JUPYTER BOOKS>

I have just tried again with my normal windows (python 3.9.0) and I got this:

sphinx-err-a0xf6a14.log

C:\Users\gaem1\Documents\JUPYTER BOOKS>jb build esempio3
Running Jupyter-Book v0.8.3
Source Folder: C:\Users\gaem1\Documents\JUPYTER BOOKS\esempio3
Config Path: C:\Users\gaem1\Documents\JUPYTER BOOKS\esempio3\_config.yml
Output Path: C:\Users\gaem1\Documents\JUPYTER BOOKS\esempio3\_build\html
Running Sphinx v3.3.1
myst v0.12.10: MdParserConfig(renderer='sphinx', commonmark_only=False, dmath_enable=True, dmath_allow_labels=True, dmath_allow_space=True, dmath_allow_digits=True, amsmath_enable=False, deflist_enable=False, update_mathjax=True, admonition_enable=False, figure_enable=False, disable_syntax=[], html_img_enable=False, url_schemes=['mailto', 'http', 'https'], heading_anchors=None)
building [mo]: targets for 0 po files that are out of date
building [html]: targets for 4 source files that are out of date
updating environment: [new config] 4 added, 0 changed, 0 removed
checking for C:\Users\gaem1\Documents\JUPYTER BOOKS\esempio3\references.bib in bibtex cache... not found
parsing bibtex file C:\Users\gaem1\Documents\JUPYTER BOOKS\esempio3\references.bib... parsed 5 entries
Executing: notebooks in: C:\Users\gaem1\Documents\JUPYTER BOOKS\esempio3

Exception occurred:
  File "c:\python39\lib\asyncio\events.py", line 504, in add_reader
    raise NotImplementedError
NotImplementedError
The full traceback has been saved in C:\Users\gaem1\AppData\Local\Temp\sphinx-err-a0xf6a14.log, if you want to report the issue to the developers.
Please also report this if it was a user error, so that a better error message can be provided next time.
A bug report can be filed in the tracker at <https://github.com/sphinx-doc/sphinx/issues>. Thanks!
Traceback (most recent call last):
  File "c:\python39\lib\site-packages\jupyter_book\sphinx.py", line 141, in build_sphinx
    app.build(force_all, filenames)
  File "c:\python39\lib\site-packages\sphinx\application.py", line 352, in build
    self.builder.build_update()
  File "c:\python39\lib\site-packages\sphinx\builders\__init__.py", line 297, in build_update
    self.build(to_build,
  File "c:\python39\lib\site-packages\sphinx\builders\__init__.py", line 311, in build
    updated_docnames = set(self.read())
  File "c:\python39\lib\site-packages\sphinx\builders\__init__.py", line 418, in read
    self._read_serial(docnames)
  File "c:\python39\lib\site-packages\sphinx\builders\__init__.py", line 439, in _read_serial
    self.read_doc(docname)
  File "c:\python39\lib\site-packages\sphinx\builders\__init__.py", line 479, in read_doc
    doctree = read_doc(self.app, self.env, self.env.doc2path(docname))
  File "c:\python39\lib\site-packages\sphinx\io.py", line 223, in read_doc
    pub.publish()
  File "c:\python39\lib\site-packages\docutils\core.py", line 217, in publish
    self.document = self.reader.read(self.source, self.parser,
  File "c:\python39\lib\site-packages\sphinx\io.py", line 128, in read
    self.parse()
  File "c:\python39\lib\site-packages\docutils\readers\__init__.py", line 77, in parse
    self.parser.parse(self.input, document)
  File "c:\python39\lib\site-packages\myst_nb\parser.py", line 75, in parse
    ntbk = generate_notebook_outputs(
  File "c:\python39\lib\site-packages\myst_nb\execution.py", line 138, in generate_notebook_outputs
    result = single_nb_execution(
  File "c:\python39\lib\site-packages\jupyter_cache\executors\utils.py", line 51, in single_nb_execution
    executenb(
  File "c:\python39\lib\site-packages\nbclient\client.py", line 1087, in execute
    return NotebookClient(nb=nb, resources=resources, km=km, **kwargs).execute()
  File "c:\python39\lib\site-packages\nbclient\util.py", line 74, in wrapped
    return just_run(coro(*args, **kwargs))
  File "c:\python39\lib\site-packages\nbclient\util.py", line 53, in just_run
    return loop.run_until_complete(coro)
  File "c:\python39\lib\asyncio\base_events.py", line 642, in run_until_complete
    return future.result()
  File "c:\python39\lib\site-packages\nbclient\client.py", line 524, in async_execute
    async with self.async_setup_kernel(**kwargs):
  File "c:\python39\lib\site-packages\async_generator\_util.py", line 34, in __aenter__
    return await self._agen.asend(None)
  File "c:\python39\lib\site-packages\nbclient\client.py", line 483, in async_setup_kernel
    await self.async_start_new_kernel_client()
  File "c:\python39\lib\site-packages\nbclient\client.py", line 408, in async_start_new_kernel_client
    await ensure_async(self.kc.start_channels())
  File "c:\python39\lib\site-packages\jupyter_client\client.py", line 106, in start_channels
    self.shell_channel.start()
  File "c:\python39\lib\site-packages\jupyter_client\client.py", line 151, in shell_channel
    socket = self.connect_shell(identity=self.session.bsession)
  File "c:\python39\lib\site-packages\jupyter_client\connect.py", line 561, in connect_shell
    return self._create_connected_socket('shell', identity=identity)
  File "c:\python39\lib\site-packages\jupyter_client\connect.py", line 545, in _create_connected_socket
    sock = self.context.socket(socket_type)
  File "c:\python39\lib\site-packages\zmq\sugar\context.py", line 226, in socket
    s = self._socket_class(self, socket_type, **kwargs)
  File "c:\python39\lib\site-packages\zmq\_future.py", line 144, in __init__
    self._init_io_state()
  File "c:\python39\lib\site-packages\zmq\asyncio.py", line 56, in _init_io_state
    self.io_loop.add_reader(self._fd, lambda: self._handle_events(0, 0))
  File "c:\python39\lib\asyncio\events.py", line 504, in add_reader
    raise NotImplementedError
NotImplementedError

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

Traceback (most recent call last):
  File "c:\python39\lib\runpy.py", line 197, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "c:\python39\lib\runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "C:\Python39\Scripts\jb.exe\__main__.py", line 7, in <module>
  File "c:\python39\lib\site-packages\click\core.py", line 829, in __call__
    return self.main(*args, **kwargs)
  File "c:\python39\lib\site-packages\click\core.py", line 782, in main
    rv = self.invoke(ctx)
  File "c:\python39\lib\site-packages\click\core.py", line 1259, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "c:\python39\lib\site-packages\click\core.py", line 1066, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "c:\python39\lib\site-packages\click\core.py", line 610, in invoke
    return callback(*args, **kwargs)
  File "c:\python39\lib\site-packages\jupyter_book\commands\__init__.py", line 259, in build
    builder_specific_actions(
  File "c:\python39\lib\site-packages\jupyter_book\commands\__init__.py", line 500, 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.

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

Error in atexit._run_exitfuncs:
Traceback (most recent call last):
  File "c:\python39\lib\site-packages\nbclient\client.py", line 365, in _async_cleanup_kernel
    await ensure_async(self.kc.stop_channels())
  File "c:\python39\lib\site-packages\jupyter_client\client.py", line 125, in stop_channels
    if self.shell_channel.is_alive():
  File "c:\python39\lib\site-packages\jupyter_client\client.py", line 151, in shell_channel
    socket = self.connect_shell(identity=self.session.bsession)
  File "c:\python39\lib\site-packages\jupyter_client\connect.py", line 561, in connect_shell
    return self._create_connected_socket('shell', identity=identity)
  File "c:\python39\lib\site-packages\jupyter_client\connect.py", line 545, in _create_connected_socket
    sock = self.context.socket(socket_type)
  File "c:\python39\lib\site-packages\zmq\sugar\context.py", line 226, in socket
    s = self._socket_class(self, socket_type, **kwargs)
  File "c:\python39\lib\site-packages\zmq\_future.py", line 144, in __init__
    self._init_io_state()
  File "c:\python39\lib\site-packages\zmq\asyncio.py", line 56, in _init_io_state
    self.io_loop.add_reader(self._fd, lambda: self._handle_events(0, 0))
  File "c:\python39\lib\asyncio\events.py", line 504, in add_reader
    raise NotImplementedError
NotImplementedError
Exception ignored in: <function Socket.__del__ at 0x000002CEF4769A60>
Traceback (most recent call last):
  File "c:\python39\lib\site-packages\zmq\sugar\socket.py", line 68, in __del__
    self.close()
  File "c:\python39\lib\site-packages\zmq\_future.py", line 160, in close
    self._clear_io_state()
  File "c:\python39\lib\site-packages\zmq\asyncio.py", line 63, in _clear_io_state
    self.io_loop.remove_reader(self._fd)
  File "c:\python39\lib\asyncio\events.py", line 507, in remove_reader
    raise NotImplementedError
NotImplementedError:
Exception ignored in: <function Socket.__del__ at 0x000002CEF4769A60>
Traceback (most recent call last):
  File "c:\python39\lib\site-packages\zmq\sugar\socket.py", line 68, in __del__
  File "c:\python39\lib\site-packages\zmq\_future.py", line 160, in close
  File "c:\python39\lib\site-packages\zmq\asyncio.py", line 63, in _clear_io_state
  File "c:\python39\lib\asyncio\events.py", line 507, in remove_reader
NotImplementedError:

C:\Users\gaem1\Documents\JUPYTER BOOKS>

[luukalt]

It worked! (python 3.7.9) @Dedalo01

I owe you big time. I made the adjustments to the init.py and your step 2 and 3.
How can you force an environment to always install sphinxcontrib-bibtex==1.0.0.
Adding it to requirements apparently did not help.

[Dedalo01]

lol I'm happy to have helped you @luukalt ... now I have to understand why it works on my ubuntu virtual box, but on windows 10 it doesn't 🤣
... I think that is python 3.9.0 or 3.8 that doesn't work on my machine... i will try with python 3.7.9!

EDIT:
OK IT WORKED FLAWLESSY THIS TIME!!
I was right! Python 3.9.0 and Python 3.8.5 don't work on windows 10 with jupyter book (at least on my machine...)

Step that I did to make Jupyter Book working on my pc:

1. Install Anaconda Individual Edition
2. Launch Anaconda Navigator
3. Go to Environments
4. Create a new Environment and call it as you wish, select Python version 3.7
5. Click the green button and select Open Terminal

Now from the terminal follow these steps:

1. pip install -U jupyter-book
2. pip uninstall sphinxcontrib-bibtex
3. pip install sphinxcontrib-bibtex==1.0.0
4. Now out of the terminal, go and find your "_ _init_ _.py" (low dash_low dash_init_low dash_low dash_.py, all united) (mine was in "something\site-packages\jupyter_book\commands\", you have to find where Anaconda installed it)
5. Open the file with an editor and modify these lines:
   # build_modified = max([os.stat(ii).st_mtime for ii in build_files]) (comment this out with #)
   freshenv = True (set this to True)
6. Save the file and go back to the terminal
7. cd (Go to a folder of your choiche)
8. jb create (Name of your choiche)
9. jb build (same name as before)
10. you should see something like this:

(jb_python_3_7_9) C:\Users\gaem1\Documents\JUPYTER BOOKS>jb build esempio3
Running Jupyter-Book v0.8.3
Source Folder: C:\Users\gaem1\Documents\JUPYTER BOOKS\esempio3
Config Path: C:\Users\gaem1\Documents\JUPYTER BOOKS\esempio3\_config.yml
Output Path: C:\Users\gaem1\Documents\JUPYTER BOOKS\esempio3\_build\html
Running Sphinx v3.3.1
myst v0.12.10: MdParserConfig(renderer='sphinx', commonmark_only=False, dmath_enable=True, dmath_allow_labels=True, dmath_allow_space=True, dmath_allow_digits=True, amsmath_enable=False, deflist_enable=False, update_mathjax=True, admonition_enable=False, figure_enable=False, disable_syntax=[], html_img_enable=False, url_schemes=['mailto', 'http', 'https'], heading_anchors=None)
building [mo]: targets for 0 po files that are out of date
building [html]: targets for 4 source files that are out of date
updating environment: [new config] 4 added, 0 changed, 0 removed
reading sources... [ 25%] content                          reading sources... [ 50%] intro                            reading sources... [ 75%] markdown                         checking for C:\Users\gaem1\Documents\JUPYTER BOOKS\esempio3\references.bib in bibtex cache... not found
parsing bibtex file C:\Users\gaem1\Documents\JUPYTER BOOKS\esempio3\references.bib... parsed 5 entries
reading sources... [100%] notebooks                        Executing: notebooks in: C:\Users\gaem1\Documents\JUPYTER BOOKS\esempio3

WARNING: Execution Failed with traceback saved in C:\Users\gaem1\Documents\JUPYTER BOOKS\esempio3\_build\html\reports\notebooks.log
looking for now-outdated files... none found
pickling environment... done
checking consistency... done
preparing documents... done
writing output... [ 25%] content                           writing output... [ 50%] intro                             writing output... [ 75%] markdown                          writing output... [100%] notebooks                         
generating indices... genindex done
writing additional pages... search done
copying static files... done
copying extra files... done
dumping search index in English (code: en)... done
dumping object inventory... done
build succeeded, 1 warning.

The HTML pages are in esempio3\_build\html.

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

Finished generating HTML for book.
Your book's HTML pages are here:
    esempio3\_build\html\
You can look at your book by opening this file in a browser:
    esempio3\_build\html\index.html
Or paste this line directly into your browser bar:
    file://C:\Users\gaem1\Documents\JUPYTER BOOKS\esempio3\_build\html\index.html          

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


(jb_python_3_7_9) C:\Users\gaem1\Documents\JUPYTER BOOKS>

I wanted to thank all of you who helped me understand and solve the problem !!!!!
@choldgraf @fcharih and @lewtun !!!!!!

[luukalt]

When I rebuild the book, I do get errors again.

(wintest5) C:\Users\laaltenburg>jb build testbook
Running Jupyter-Book v0.8.3
Source Folder: C:\Users\laaltenburg\testbook
Config Path: C:\Users\laaltenburg\testbook\_config.yml
Output Path: C:\Users\laaltenburg\testbook\_build\html
Running Sphinx v2.4.4

Extension error:
Could not import extension myst_nb (exception: No module named 'IPython.lib')
Traceback (most recent call last):
  File "c:\users\laaltenburg\.conda\envs\wintest5\lib\site-packages\sphinx\registry.py", line 453, in load_extension
    mod = import_module(extname)
  File "c:\users\laaltenburg\.conda\envs\wintest5\lib\importlib\__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
  File "<frozen importlib._bootstrap>", line 983, in _find_and_load
  File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 677, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 728, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "c:\users\laaltenburg\.conda\envs\wintest5\lib\site-packages\myst_nb\__init__.py", line 17, in <module>
    from IPython.lib.lexers import IPythonTracebackLexer, IPython3Lexer
ModuleNotFoundError: No module named 'IPython.lib'

Ipython is installed.

[Dedalo01]

wait I think you have to spell it as iPython if I am not wrong @luukalt

[luukalt]

This happens when I run:

jb build testbook

The module is installed already.

[Dedalo01]

ok try with this pip install ipython @lewtun

[choldgraf]

hey @deedalo01 and @luukalt - it's a bit hard for me to figure out if this is resolved or not. Can you upgrade to the latest Jupyter Book (v0.9.0) which pins sphinxcontrib-bibtex, and if you're still getting errors, paste minimal steps that will reproduce them?

[Dedalo01]

@choldgraf ok I created another environment with Anaconda, using always Python 3.7.9 and I installed jupyter book v0.9.1 and IT WORKED WITHOUT ANY ERROR!! :

(jb-0-9_py_3-7) C:\Users\gaem1\Documents\JUPYTER BOOKS\jupyter book v0-9-0 prova>jb create esempio1

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

Your book template can be found at

    esempio1\

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


(jb-0-9_py_3-7) C:\Users\gaem1\Documents\JUPYTER BOOKS\jupyter book v0-9-0 prova>jb build esempio1
Running Jupyter-Book v0.9.1
Source Folder: C:\Users\gaem1\Documents\JUPYTER BOOKS\jupyter book v0-9-0 prova\esempio1
Config Path: C:\Users\gaem1\Documents\JUPYTER BOOKS\jupyter book v0-9-0 prova\esempio1\_config.yml
Output Path: C:\Users\gaem1\Documents\JUPYTER BOOKS\jupyter book v0-9-0 prova\esempio1\_build\html
Running Sphinx v3.4.1
making output directory... done
myst v0.12.10: MdParserConfig(renderer='sphinx', commonmark_only=False, dmath_enable=True, dmath_allow_labels=True, dmath_allow_space=True, dmath_allow_digits=True, amsmath_enable=False, deflist_enable=False, update_mathjax=True, admonition_enable=False, figure_enable=False, disable_syntax=[], html_img_enable=False, url_schemes=['mailto', 'http', 'https'], heading_anchors=None)
building [mo]: targets for 0 po files that are out of date
building [html]: targets for 4 source files that are out of date
updating environment: [new config] 4 added, 0 changed, 0 removed
reading sources... [ 25%] content                                     reading sources... [ 50%] intro                                       reading sources... [ 75%] markdown                                    checking for C:\Users\gaem1\Documents\JUPYTER BOOKS\jupyter book v0-9-0 prova\esempio1\references.bib in bibtex cache... not found
parsing bibtex file C:\Users\gaem1\Documents\JUPYTER BOOKS\jupyter book v0-9-0 prova\esempio1\references.bib... parsed 5 entries
reading sources... [100%] notebooks                                   Executing: notebooks in: C:\Users\gaem1\Documents\JUPYTER BOOKS\jupyter book v0-9-0 prova\esempio1

WARNING: Execution Failed with traceback saved in C:\Users\gaem1\Documents\JUPYTER BOOKS\jupyter book v0-9-0 prova\esempio1\_build\html\reports\notebooks.log
looking for now-outdated files... none found
pickling environment... done
checking consistency... done
preparing documents... done
writing output... [ 25%] content                                      writing output... [ 50%] intro                                        writing output... [ 75%] markdown                                     writing output... [100%] notebooks                                    
generating indices... genindex done
writing additional pages... search done
copying static files... done
copying extra files... done
dumping search index in English (code: en)... done
dumping object inventory... done
build succeeded, 1 warning.

The HTML pages are in esempio1\_build\html.

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

Finished generating HTML for book.
Your book's HTML pages are here:
    esempio1\_build\html\
You can look at your book by opening this file in a browser:
    esempio1\_build\html\index.html
Or paste this line directly into your browser bar:
    file://C:\Users\gaem1\Documents\JUPYTER BOOKS\jupyter book v0-9-0 prova\esempio1\_build\html\index.html

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


(jb-0-9_py_3-7) C:\Users\gaem1\Documents\JUPYTER BOOKS\jupyter book v0-9-0 prova>

Under here there is a fresh installation of Jupyter Book v0.9.1 on my Anaconda environment (Python 3.7.9):

(jb-0-9_py_3-7) C:\Users\gaem1>pip install -U jupyter-book
Collecting jupyter-book
  Using cached jupyter_book-0.9.1-py3-none-any.whl (47 kB)
Requirement already satisfied: setuptools in c:\users\gaem1\anaconda3\envs\jb-0-9_py_3-7\lib\site-packages (from jupyter-book) (51.0.0.post20201207)
Collecting docutils>=0.15
  Using cached docutils-0.16-py2.py3-none-any.whl (548 kB)
Collecting myst-nb~=0.10.1
  Using cached myst_nb-0.10.1-py3-none-any.whl (36 kB)
Collecting ipywidgets<8,>=7.0.0
  Downloading ipywidgets-7.6.2-py2.py3-none-any.whl (121 kB)
     |████████████████████████████████| 121 kB 3.2 MB/s
Collecting ipykernel>=4.5.1
  Using cached ipykernel-5.4.2-py3-none-any.whl (119 kB)
Collecting ipython
  Using cached ipython-7.19.0-py3-none-any.whl (784 kB)
Collecting jedi>=0.10
  Downloading jedi-0.18.0-py2.py3-none-any.whl (1.4 MB)
     |████████████████████████████████| 1.4 MB 1.3 MB/s
Collecting jupyter-cache~=0.4.1
  Using cached jupyter_cache-0.4.1-py3-none-any.whl (31 kB)
Collecting jupyter-sphinx~=0.3.1
  Using cached jupyter_sphinx-0.3.2-py3-none-any.whl (20 kB)
Collecting jupyterlab-widgets>=1.0.0
  Downloading jupyterlab_widgets-1.0.0-py3-none-any.whl (243 kB)
     |████████████████████████████████| 243 kB 3.2 MB/s
Collecting myst-parser~=0.12.9
  Using cached myst_parser-0.12.10-py3-none-any.whl (34 kB)
Collecting markdown-it-py~=0.5.4
  Using cached markdown_it_py-0.5.8-py3-none-any.whl (110 kB)
Collecting attrs
  Using cached attrs-20.3.0-py2.py3-none-any.whl (49 kB)
Collecting nbclient<0.6,>=0.2
  Using cached nbclient-0.5.1-py3-none-any.whl (65 kB)
Collecting jupyter-client
  Using cached jupyter_client-6.1.7-py3-none-any.whl (108 kB)
Collecting jupyter-core>=4.6.0
  Using cached jupyter_core-4.7.0-py3-none-any.whl (82 kB)
Collecting nbconvert<6
  Using cached nbconvert-5.6.1-py2.py3-none-any.whl (455 kB)
Collecting entrypoints>=0.2.2
  Using cached entrypoints-0.3-py2.py3-none-any.whl (11 kB)
Collecting jinja2>=2.4
  Using cached Jinja2-2.11.2-py2.py3-none-any.whl (125 kB)
Collecting MarkupSafe>=0.23
  Using cached MarkupSafe-1.1.1-cp37-cp37m-win_amd64.whl (16 kB)
Collecting mistune<2,>=0.8.1
  Using cached mistune-0.8.4-py2.py3-none-any.whl (16 kB)
Collecting nbformat
  Using cached nbformat-5.0.8-py3-none-any.whl (172 kB)
Collecting jsonschema
  Using cached jsonschema-3.2.0-py2.py3-none-any.whl (56 kB)
Collecting nested-lookup~=0.2.21
  Using cached nested-lookup-0.2.21.tar.gz (7.8 kB)
Collecting pandocfilters>=1.4.1
  Using cached pandocfilters-1.4.3-py3-none-any.whl
Collecting parso<0.9.0,>=0.8.0
  Downloading parso-0.8.1-py2.py3-none-any.whl (93 kB)
     |████████████████████████████████| 93 kB 777 kB/s
Collecting prompt-toolkit!=3.0.0,!=3.0.1,<3.1.0,>=2.0.0
  Using cached prompt_toolkit-3.0.8-py3-none-any.whl (355 kB)
Collecting pyrsistent>=0.14.0
  Using cached pyrsistent-0.17.3-cp37-cp37m-win_amd64.whl
Collecting python-dateutil>=2.1
  Using cached python_dateutil-2.8.1-py2.py3-none-any.whl (227 kB)
Collecting pywin32>=1.0
  Using cached pywin32-300-cp37-cp37m-win_amd64.whl (9.2 MB)
Collecting pyzmq>=13
  Using cached pyzmq-20.0.0-cp37-cp37m-win_amd64.whl (1.0 MB)
Collecting six>=1.11.0
  Using cached six-1.15.0-py2.py3-none-any.whl (10 kB)
Collecting sphinx<4,>=2
  Downloading Sphinx-3.4.1-py3-none-any.whl (2.9 MB)
     |████████████████████████████████| 2.9 MB 2.2 MB/s
Collecting alabaster<0.8,>=0.7
  Using cached alabaster-0.7.12-py2.py3-none-any.whl (14 kB)
Collecting babel>=1.3
  Using cached Babel-2.9.0-py2.py3-none-any.whl (8.8 MB)
Collecting colorama
  Using cached colorama-0.4.4-py2.py3-none-any.whl (16 kB)
Collecting pygments
  Using cached Pygments-2.7.3-py3-none-any.whl (950 kB)
Collecting pytz>=2015.7
  Using cached pytz-2020.5-py2.py3-none-any.whl (510 kB)
Collecting requests>=2.5.0
  Using cached requests-2.25.1-py2.py3-none-any.whl (61 kB)
Requirement already satisfied: certifi>=2017.4.17 in c:\users\gaem1\anaconda3\envs\jb-0-9_py_3-7\lib\site-packages (from requests>=2.5.0->sphinx<4,>=2->jupyter-book) (2020.12.5)
Collecting chardet<5,>=3.0.2
  Using cached chardet-4.0.0-py2.py3-none-any.whl (178 kB)
Collecting idna<3,>=2.5
  Using cached idna-2.10-py2.py3-none-any.whl (58 kB)
Collecting snowballstemmer>=1.1
  Using cached snowballstemmer-2.0.0-py2.py3-none-any.whl (97 kB)
Collecting sphinx-book-theme>=0.0.39
  Using cached sphinx_book_theme-0.0.39-py3-none-any.whl (86 kB)
Collecting pydata-sphinx-theme~=0.4.1
  Using cached pydata_sphinx_theme-0.4.1-py3-none-any.whl (2.1 MB)
Collecting sphinx-panels~=0.5.2
  Using cached sphinx_panels-0.5.2-py3-none-any.whl (87 kB)
Collecting sphinx-thebe>=0.0.6
  Using cached sphinx_thebe-0.0.8-py3-none-any.whl (7.4 kB)
Collecting sphinx-togglebutton
  Using cached sphinx_togglebutton-0.2.3-py3-none-any.whl (6.1 kB)
Requirement already satisfied: wheel in c:\users\gaem1\anaconda3\envs\jb-0-9_py_3-7\lib\site-packages (from sphinx-togglebutton->jupyter-book) (0.36.2)
Collecting sphinxcontrib-bibtex~=1.0.0
  Using cached sphinxcontrib_bibtex-1.0.0-py3-none-any.whl (14 kB)
Collecting oset>=0.1.3
  Using cached oset-0.1.3-py3-none-any.whl
Collecting pybtex>=0.20
  Using cached pybtex-0.23.0-py2.py3-none-any.whl (279 kB)
Collecting latexcodec>=1.0.4
  Using cached latexcodec-2.0.1-py2.py3-none-any.whl (18 kB)
Collecting pybtex-docutils>=0.2.0
  Using cached pybtex_docutils-0.2.2-py2.py3-none-any.whl (4.6 kB)
Collecting pyyaml
  Using cached PyYAML-5.3.1-cp37-cp37m-win_amd64.whl (216 kB)
Collecting sqlalchemy~=1.3.12
  Downloading SQLAlchemy-1.3.22-cp37-cp37m-win_amd64.whl (1.2 MB)
     |████████████████████████████████| 1.2 MB 2.2 MB/s
Collecting tornado>=4.2
  Using cached tornado-6.1-cp37-cp37m-win_amd64.whl (422 kB)
Collecting traitlets>=4.3.1
  Using cached traitlets-5.0.5-py3-none-any.whl (100 kB)
Collecting urllib3<1.27,>=1.21.1
  Using cached urllib3-1.26.2-py2.py3-none-any.whl (136 kB)
Collecting widgetsnbextension~=3.5.0
  Using cached widgetsnbextension-3.5.1-py2.py3-none-any.whl (2.2 MB)
Collecting notebook>=4.4.1
  Downloading notebook-6.1.6-py3-none-any.whl (9.5 MB)
     |████████████████████████████████| 9.5 MB 819 kB/s
Collecting terminado>=0.8.3
  Using cached terminado-0.9.1-py3-none-any.whl (13 kB)
Collecting pywinpty>=0.5
  Using cached pywinpty-0.5.7-cp37-cp37m-win_amd64.whl (1.3 MB)
Collecting argon2-cffi
  Using cached argon2_cffi-20.1.0-cp37-cp37m-win_amd64.whl (42 kB)
Collecting cffi>=1.0.0
  Using cached cffi-1.14.4-cp37-cp37m-win_amd64.whl (178 kB)
Collecting async-generator
  Using cached async_generator-1.10-py3-none-any.whl (18 kB)
Collecting backcall
  Using cached backcall-0.2.0-py2.py3-none-any.whl (11 kB)
Collecting beautifulsoup4
  Using cached beautifulsoup4-4.9.3-py3-none-any.whl (115 kB)
Collecting soupsieve>1.2
  Using cached soupsieve-2.1-py3-none-any.whl (32 kB)
Collecting bleach
  Using cached bleach-3.2.1-py2.py3-none-any.whl (145 kB)
Collecting click
  Using cached click-7.1.2-py2.py3-none-any.whl (82 kB)
Collecting decorator
  Using cached decorator-4.4.2-py2.py3-none-any.whl (9.2 kB)
Collecting defusedxml
  Using cached defusedxml-0.6.0-py2.py3-none-any.whl (23 kB)
Collecting imagesize
  Using cached imagesize-1.2.0-py2.py3-none-any.whl (4.8 kB)
Collecting importlib-metadata
  Using cached importlib_metadata-3.3.0-py3-none-any.whl (10 kB)
Collecting typing-extensions>=3.6.4
  Using cached typing_extensions-3.7.4.3-py3-none-any.whl (22 kB)
Collecting zipp>=0.5
  Using cached zipp-3.4.0-py3-none-any.whl (5.2 kB)
Collecting ipython-genutils
  Using cached ipython_genutils-0.2.0-py2.py3-none-any.whl (26 kB)
Collecting nbdime
  Using cached nbdime-2.1.0-py2.py3-none-any.whl (5.0 MB)
Collecting GitPython!=2.1.4,!=2.1.5,!=2.1.6
  Using cached GitPython-3.1.11-py3-none-any.whl (159 kB)
Collecting gitdb<5,>=4.0.1
  Using cached gitdb-4.0.5-py3-none-any.whl (63 kB)
Collecting smmap<4,>=3.0.1
  Using cached smmap-3.0.4-py2.py3-none-any.whl (25 kB)
Collecting nest-asyncio
  Using cached nest_asyncio-1.4.3-py3-none-any.whl (5.3 kB)
Collecting packaging
  Using cached packaging-20.8-py2.py3-none-any.whl (39 kB)
Collecting pyparsing>=2.0.2
  Using cached pyparsing-2.4.7-py2.py3-none-any.whl (67 kB)
Collecting pickleshare
  Using cached pickleshare-0.7.5-py2.py3-none-any.whl (6.9 kB)
Collecting prometheus-client
  Using cached prometheus_client-0.9.0-py2.py3-none-any.whl (53 kB)
Collecting pycparser
  Using cached pycparser-2.20-py2.py3-none-any.whl (112 kB)
Collecting Send2Trash
  Using cached Send2Trash-1.5.0-py3-none-any.whl (12 kB)
Collecting sphinx-comments
  Using cached sphinx_comments-0.0.3-py3-none-any.whl (4.6 kB)
Collecting sphinx-copybutton
  Using cached sphinx_copybutton-0.3.1-py3-none-any.whl (10 kB)
Collecting sphinxcontrib-applehelp
  Using cached sphinxcontrib_applehelp-1.0.2-py2.py3-none-any.whl (121 kB)
Collecting sphinxcontrib-devhelp
  Using cached sphinxcontrib_devhelp-1.0.2-py2.py3-none-any.whl (84 kB)
Collecting sphinxcontrib-htmlhelp
  Using cached sphinxcontrib_htmlhelp-1.0.3-py2.py3-none-any.whl (96 kB)
Collecting sphinxcontrib-jsmath
  Using cached sphinxcontrib_jsmath-1.0.1-py2.py3-none-any.whl (5.1 kB)
Collecting sphinxcontrib-qthelp
  Using cached sphinxcontrib_qthelp-1.0.3-py2.py3-none-any.whl (90 kB)
Collecting sphinxcontrib-serializinghtml
  Using cached sphinxcontrib_serializinghtml-1.1.4-py2.py3-none-any.whl (89 kB)
Collecting testpath
  Using cached testpath-0.4.4-py2.py3-none-any.whl (163 kB)
Collecting wcwidth
  Using cached wcwidth-0.2.5-py2.py3-none-any.whl (30 kB)
Collecting webencodings
  Using cached webencodings-0.5.1-py2.py3-none-any.whl (11 kB)
Building wheels for collected packages: nested-lookup
  Building wheel for nested-lookup (setup.py) ... done
  Created wheel for nested-lookup: filename=nested_lookup-0.2.21-py3-none-any.whl size=7578 sha256=6ddee92e8f6d59e82fd7f9d566723247728f31ba31c40ffd64ea08f67f0f8ea1
  Stored in directory: c:\users\gaem1\appdata\local\pip\cache\wheels\f8\c8\ec\74d049bd701e80649cdcc90fd4c5df174f39eea0f201564e21
Successfully built nested-lookup
Installing collected packages: zipp, typing-extensions, ipython-genutils, wcwidth, traitlets, six, pywin32, pyrsistent, pyparsing, parso, importlib-metadata, attrs, webencodings, tornado, pyzmq, python-dateutil, pygments, pycparser, prompt-toolkit, pickleshare, packaging, MarkupSafe, jupyter-core, jsonschema, jedi, decorator, colorama, backcall, testpath, pywinpty, pandocfilters, nbformat, mistune, jupyter-client, jinja2, ipython, entrypoints, defusedxml, cffi, bleach, terminado, smmap, Send2Trash, prometheus-client, nbconvert, ipykernel, argon2-cffi, urllib3, pytz, notebook, idna, gitdb, chardet, widgetsnbextension, sphinxcontrib-serializinghtml, sphinxcontrib-qthelp, sphinxcontrib-jsmath, sphinxcontrib-htmlhelp, sphinxcontrib-devhelp, sphinxcontrib-applehelp, snowballstemmer, requests, pyyaml, nest-asyncio, latexcodec, jupyterlab-widgets, imagesize, GitPython, docutils, babel, async-generator, alabaster, sqlalchemy, sphinx, soupsieve, pybtex, nbdime, nbclient, markdown-it-py, ipywidgets, sphinx-togglebutton, pydata-sphinx-theme, pybtex-docutils, oset, myst-parser, jupyter-sphinx, jupyter-cache, click, beautifulsoup4, sphinxcontrib-bibtex, sphinx-thebe, sphinx-panels, sphinx-copybutton, sphinx-comments, sphinx-book-theme, nested-lookup, myst-nb, jupyter-book
Successfully installed GitPython-3.1.11 MarkupSafe-1.1.1 Send2Trash-1.5.0 alabaster-0.7.12 argon2-cffi-20.1.0 async-generator-1.10 attrs-20.3.0 babel-2.9.0 backcall-0.2.0 beautifulsoup4-4.9.3 bleach-3.2.1 cffi-1.14.4 chardet-4.0.0 click-7.1.2 colorama-0.4.4 decorator-4.4.2 defusedxml-0.6.0 docutils-0.16 entrypoints-0.3 gitdb-4.0.5 idna-2.10 imagesize-1.2.0 importlib-metadata-3.3.0 ipykernel-5.4.2 ipython-7.19.0 ipython-genutils-0.2.0 ipywidgets-7.6.2 jedi-0.18.0 jinja2-2.11.2 jsonschema-3.2.0 jupyter-book-0.9.1 jupyter-cache-0.4.1 jupyter-client-6.1.7 jupyter-core-4.7.0 jupyter-sphinx-0.3.2 jupyterlab-widgets-1.0.0 latexcodec-2.0.1 markdown-it-py-0.5.8 mistune-0.8.4 myst-nb-0.10.1 myst-parser-0.12.10 nbclient-0.5.1 nbconvert-5.6.1 nbdime-2.1.0 nbformat-5.0.8 nest-asyncio-1.4.3 nested-lookup-0.2.21 notebook-6.1.6 oset-0.1.3 packaging-20.8 pandocfilters-1.4.3 parso-0.8.1 pickleshare-0.7.5 prometheus-client-0.9.0 prompt-toolkit-3.0.8 pybtex-0.23.0 pybtex-docutils-0.2.2 pycparser-2.20 pydata-sphinx-theme-0.4.1 pygments-2.7.3 pyparsing-2.4.7 pyrsistent-0.17.3 python-dateutil-2.8.1 pytz-2020.5 pywin32-300 pywinpty-0.5.7 pyyaml-5.3.1 pyzmq-20.0.0 requests-2.25.1 six-1.15.0 smmap-3.0.4 snowballstemmer-2.0.0 soupsieve-2.1 sphinx-3.4.1 sphinx-book-theme-0.0.39 sphinx-comments-0.0.3 sphinx-copybutton-0.3.1 sphinx-panels-0.5.2 sphinx-thebe-0.0.8 sphinx-togglebutton-0.2.3 sphinxcontrib-applehelp-1.0.2 sphinxcontrib-bibtex-1.0.0 sphinxcontrib-devhelp-1.0.2 sphinxcontrib-htmlhelp-1.0.3 sphinxcontrib-jsmath-1.0.1 sphinxcontrib-qthelp-1.0.3 sphinxcontrib-serializinghtml-1.1.4 sqlalchemy-1.3.22 terminado-0.9.1 testpath-0.4.4 tornado-6.1 traitlets-5.0.5 typing-extensions-3.7.4.3 urllib3-1.26.2 wcwidth-0.2.5 webencodings-0.5.1 widgetsnbextension-3.5.1 zipp-3.4.0

While on my PC with Python 3.9.0 It doesn't work showing this :

sphinx-err-rq6wf8sf.log

C:\Users\gaem1\Documents\JUPYTER BOOKS\jupyter book v0-9-0 prova>jb build esempio1
Running Jupyter-Book v0.9.1
Source Folder: C:\Users\gaem1\Documents\JUPYTER BOOKS\jupyter book v0-9-0 prova\esempio1
Config Path: C:\Users\gaem1\Documents\JUPYTER BOOKS\jupyter book v0-9-0 prova\esempio1\_config.yml
Output Path: C:\Users\gaem1\Documents\JUPYTER BOOKS\jupyter book v0-9-0 prova\esempio1\_build\html
Running Sphinx v3.3.1
making output directory... done
myst v0.12.10: MdParserConfig(renderer='sphinx', commonmark_only=False, dmath_enable=True, dmath_allow_labels=True, dmath_allow_space=True, dmath_allow_digits=True, amsmath_enable=False, deflist_enable=False, update_mathjax=True, admonition_enable=False, figure_enable=False, disable_syntax=[], html_img_enable=False, url_schemes=['mailto', 'http', 'https'], heading_anchors=None)
building [mo]: targets for 0 po files that are out of date
building [html]: targets for 4 source files that are out of date
updating environment: [new config] 4 added, 0 changed, 0 removed
reading sources... [ 25%] content                               reading sources... [ 50%] intro                                 reading sources... [ 75%] markdown                              checking for C:\Users\gaem1\Documents\JUPYTER BOOKS\jupyter book v0-9-0 prova\esempio1\references.bib in bibtex cache... not found
parsing bibtex file C:\Users\gaem1\Documents\JUPYTER BOOKS\jupyter book v0-9-0 prova\esempio1\references.bib... parsed 5 entries
reading sources... [100%] notebooks                             Executing: notebooks in: C:\Users\gaem1\Documents\JUPYTER BOOKS\jupyter book v0-9-0 prova\esempio1

Exception occurred:
  File "c:\python39\lib\asyncio\events.py", line 504, in add_reader
    raise NotImplementedError
NotImplementedError
The full traceback has been saved in C:\Users\gaem1\AppData\Local\Temp\sphinx-err-rq6wf8sf.log, if you want to report the issue to the developers.
Please also report this if it was a user error, so that a better error message can be provided next time.
A bug report can be filed in the tracker at <https://github.com/sphinx-doc/sphinx/issues>. Thanks!
Traceback (most recent call last):
  File "c:\python39\lib\site-packages\jupyter_book\sphinx.py", line 150, in build_sphinx
    app.build(force_all, filenames)
  File "c:\python39\lib\site-packages\sphinx\application.py", line 352, in build
    self.builder.build_update()
  File "c:\python39\lib\site-packages\sphinx\builders\__init__.py", line 297, in build_update
    self.build(to_build,
  File "c:\python39\lib\site-packages\sphinx\builders\__init__.py", line 311, in build
    updated_docnames = set(self.read())
  File "c:\python39\lib\site-packages\sphinx\builders\__init__.py", line 418, in read
    self._read_serial(docnames)
  File "c:\python39\lib\site-packages\sphinx\builders\__init__.py", line 439, in _read_serial
    self.read_doc(docname)
  File "c:\python39\lib\site-packages\sphinx\builders\__init__.py", line 479, in read_doc
    doctree = read_doc(self.app, self.env, self.env.doc2path(docname))
  File "c:\python39\lib\site-packages\sphinx\io.py", line 223, in read_doc
    pub.publish()
  File "c:\python39\lib\site-packages\docutils\core.py", line 217, in publish
    self.document = self.reader.read(self.source, self.parser,
  File "c:\python39\lib\site-packages\sphinx\io.py", line 128, in read
    self.parse()
  File "c:\python39\lib\site-packages\docutils\readers\__init__.py", line 77, in parse
    self.parser.parse(self.input, document)
  File "c:\python39\lib\site-packages\myst_nb\parser.py", line 75, in parse
    ntbk = generate_notebook_outputs(
  File "c:\python39\lib\site-packages\myst_nb\execution.py", line 138, in generate_notebook_outputs
    result = single_nb_execution(
  File "c:\python39\lib\site-packages\jupyter_cache\executors\utils.py", line 51, in single_nb_execution
    executenb(
  File "c:\python39\lib\site-packages\nbclient\client.py", line 1087, in execute
    return NotebookClient(nb=nb, resources=resources, km=km, **kwargs).execute()
  File "c:\python39\lib\site-packages\nbclient\util.py", line 74, in wrapped
    return just_run(coro(*args, **kwargs))
  File "c:\python39\lib\site-packages\nbclient\util.py", line 53, in just_run
    return loop.run_until_complete(coro)
  File "c:\python39\lib\asyncio\base_events.py", line 642, in run_until_complete
    return future.result()
  File "c:\python39\lib\site-packages\nbclient\client.py", line 524, in async_execute
    async with self.async_setup_kernel(**kwargs):
  File "c:\python39\lib\site-packages\async_generator\_util.py", line 34, in __aenter__
    return await self._agen.asend(None)
  File "c:\python39\lib\site-packages\nbclient\client.py", line 483, in async_setup_kernel
    await self.async_start_new_kernel_client()
  File "c:\python39\lib\site-packages\nbclient\client.py", line 408, in async_start_new_kernel_client
    await ensure_async(self.kc.start_channels())
  File "c:\python39\lib\site-packages\jupyter_client\client.py", line 106, in start_channels
    self.shell_channel.start()
  File "c:\python39\lib\site-packages\jupyter_client\client.py", line 151, in shell_channel
    socket = self.connect_shell(identity=self.session.bsession)
  File "c:\python39\lib\site-packages\jupyter_client\connect.py", line 561, in connect_shell
    return self._create_connected_socket('shell', identity=identity)
  File "c:\python39\lib\site-packages\jupyter_client\connect.py", line 545, in _create_connected_socket
    sock = self.context.socket(socket_type)
  File "c:\python39\lib\site-packages\zmq\sugar\context.py", line 226, in socket
    s = self._socket_class(self, socket_type, **kwargs)
  File "c:\python39\lib\site-packages\zmq\_future.py", line 144, in __init__
    self._init_io_state()
  File "c:\python39\lib\site-packages\zmq\asyncio.py", line 56, in _init_io_state
    self.io_loop.add_reader(self._fd, lambda: self._handle_events(0, 0))
  File "c:\python39\lib\asyncio\events.py", line 504, in add_reader
    raise NotImplementedError
NotImplementedError

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

Traceback (most recent call last):
  File "c:\python39\lib\runpy.py", line 197, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "c:\python39\lib\runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "C:\Python39\Scripts\jb.exe\__main__.py", line 7, in <module>
  File "c:\python39\lib\site-packages\click\core.py", line 829, in __call__
    return self.main(*args, **kwargs)
  File "c:\python39\lib\site-packages\click\core.py", line 782, in main
    rv = self.invoke(ctx)
  File "c:\python39\lib\site-packages\click\core.py", line 1259, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "c:\python39\lib\site-packages\click\core.py", line 1066, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "c:\python39\lib\site-packages\click\core.py", line 610, in invoke
    return callback(*args, **kwargs)
  File "c:\python39\lib\site-packages\jupyter_book\commands\__init__.py", line 303, in build
    builder_specific_actions(
  File "c:\python39\lib\site-packages\jupyter_book\commands\__init__.py", line 545, 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.

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

Error in atexit._run_exitfuncs:
Traceback (most recent call last):
  File "c:\python39\lib\site-packages\nbclient\client.py", line 365, in _async_cleanup_kernel
    await ensure_async(self.kc.stop_channels())
  File "c:\python39\lib\site-packages\jupyter_client\client.py", line 125, in stop_channels
    if self.shell_channel.is_alive():
  File "c:\python39\lib\site-packages\jupyter_client\client.py", line 151, in shell_channel
    socket = self.connect_shell(identity=self.session.bsession)
  File "c:\python39\lib\site-packages\jupyter_client\connect.py", line 561, in connect_shell
    return self._create_connected_socket('shell', identity=identity)
  File "c:\python39\lib\site-packages\jupyter_client\connect.py", line 545, in _create_connected_socket
    sock = self.context.socket(socket_type)
  File "c:\python39\lib\site-packages\zmq\sugar\context.py", line 226, in socket
    s = self._socket_class(self, socket_type, **kwargs)
  File "c:\python39\lib\site-packages\zmq\_future.py", line 144, in __init__
    self._init_io_state()
  File "c:\python39\lib\site-packages\zmq\asyncio.py", line 56, in _init_io_state
    self.io_loop.add_reader(self._fd, lambda: self._handle_events(0, 0))
  File "c:\python39\lib\asyncio\events.py", line 504, in add_reader
    raise NotImplementedError
NotImplementedError
Exception ignored in: <function Socket.__del__ at 0x0000023E5CC1AA60>
Traceback (most recent call last):
  File "c:\python39\lib\site-packages\zmq\sugar\socket.py", line 68, in __del__
    self.close()
  File "c:\python39\lib\site-packages\zmq\_future.py", line 160, in close
    self._clear_io_state()
  File "c:\python39\lib\site-packages\zmq\asyncio.py", line 63, in _clear_io_state
    self.io_loop.remove_reader(self._fd)
  File "c:\python39\lib\asyncio\events.py", line 507, in remove_reader
    raise NotImplementedError
NotImplementedError:
Exception ignored in: <function Socket.__del__ at 0x0000023E5CC1AA60>
Traceback (most recent call last):
  File "c:\python39\lib\site-packages\zmq\sugar\socket.py", line 68, in __del__
  File "c:\python39\lib\site-packages\zmq\_future.py", line 160, in close
  File "c:\python39\lib\site-packages\zmq\asyncio.py", line 63, in _clear_io_state
  File "c:\python39\lib\asyncio\events.py", line 507, in remove_reader
NotImplementedError:

C:\Users\gaem1\Documents\JUPYTER BOOKS\jupyter book v0-9-0 prova>python --version
Python 3.9.0

C:\Users\gaem1\Documents\JUPYTER BOOKS\jupyter book v0-9-0 prova>

@choldgraf Thank You for always improving this awesome Jupyter Book!

[choldgraf]

wohoo! I am glad that https://github.com/executablebooks/jupyter-book/pull/1153 seems to have worked haha