Execution Error in notebook

[kp992]

The CI build passes, but the Cell execution fails. I am able to reproduce the error locally. Steps to reproduce it (requires mojo installation locally)

1. Convert tutorial/mojo_demo.md to tutorial/mojo_demo.ipynb using jupytext.
2. Run jupyter nbconvert --execute --to html tutorial/mojo_demo.ipynb

   
   % jupyter nbconvert --execute --to html tutorial/mojo_demo.ipynb
   [NbConvertApp] Converting notebook tutorial/mojo_demo.ipynb to html
   [10266:71788:20231118,164420.155749:ERROR directory_reader_posix.cc:42] opendir /Users/kpl/.modular/crashdb/attachments/2c70c68f-1c92-43d0-83ed-a6f7c5307037: No such file or directory (2)
   Traceback (most recent call last):
   File "/Users/kpl/mambaforge/envs/qe/bin/jupyter-nbconvert", line 8, in <module>
   sys.exit(main())
   File "/Users/kpl/mambaforge/envs/qe/lib/python3.10/site-packages/jupyter_core/application.py", line 285, in launch_instance
   return super().launch_instance(argv=argv, **kwargs)
   File "/Users/kpl/mambaforge/envs/qe/lib/python3.10/site-packages/traitlets/config/application.py", line 1046, in launch_instance
   app.start()
   File "/Users/kpl/mambaforge/envs/qe/lib/python3.10/site-packages/nbconvert/nbconvertapp.py", line 410, in start
   self.convert_notebooks()
   File "/Users/kpl/mambaforge/envs/qe/lib/python3.10/site-packages/nbconvert/nbconvertapp.py", line 585, in convert_notebooks
   self.convert_single_notebook(notebook_filename)
   File "/Users/kpl/mambaforge/envs/qe/lib/python3.10/site-packages/nbconvert/nbconvertapp.py", line 551, in convert_single_notebook
   output, resources = self.export_single_notebook(
   File "/Users/kpl/mambaforge/envs/qe/lib/python3.10/site-packages/nbconvert/nbconvertapp.py", line 477, in export_single_notebook
   output, resources = self.exporter.from_filename(
   File "/Users/kpl/mambaforge/envs/qe/lib/python3.10/site-packages/nbconvert/exporters/templateexporter.py", line 389, in from_filename
   return super().from_filename(filename, resources, **kw)  # type:ignore
   File "/Users/kpl/mambaforge/envs/qe/lib/python3.10/site-packages/nbconvert/exporters/exporter.py", line 201, in from_filename
   return self.from_file(f, resources=resources, **kw)
   File "/Users/kpl/mambaforge/envs/qe/lib/python3.10/site-packages/nbconvert/exporters/templateexporter.py", line 395, in from_file
   return super().from_file(file_stream, resources, **kw)  # type:ignore
   File "/Users/kpl/mambaforge/envs/qe/lib/python3.10/site-packages/nbconvert/exporters/exporter.py", line 220, in from_file
   return self.from_notebook_node(
   File "/Users/kpl/mambaforge/envs/qe/lib/python3.10/site-packages/nbconvert/exporters/html.py", line 260, in from_notebook_node
   html, resources = super().from_notebook_node(nb, resources, **kw)
   File "/Users/kpl/mambaforge/envs/qe/lib/python3.10/site-packages/nbconvert/exporters/templateexporter.py", line 411, in from_notebook_node
   nb_copy, resources = super().from_notebook_node(nb, resources, **kw)
   File "/Users/kpl/mambaforge/envs/qe/lib/python3.10/site-packages/nbconvert/exporters/exporter.py", line 154, in from_notebook_node
   nb_copy, resources = self._preprocess(nb_copy, resources)
   File "/Users/kpl/mambaforge/envs/qe/lib/python3.10/site-packages/nbconvert/exporters/exporter.py", line 352, in _preprocess
   nbc, resc = preprocessor(nbc, resc)
   File "/Users/kpl/mambaforge/envs/qe/lib/python3.10/site-packages/nbconvert/preprocessors/base.py", line 48, in __call__
   return self.preprocess(nb, resources)
   File "/Users/kpl/mambaforge/envs/qe/lib/python3.10/site-packages/nbconvert/preprocessors/execute.py", line 100, in preprocess
   self.preprocess_cell(cell, resources, index)
   File "/Users/kpl/mambaforge/envs/qe/lib/python3.10/site-packages/nbconvert/preprocessors/execute.py", line 121, in preprocess_cell
   cell = self.execute_cell(cell, index, store_history=True)
   File "/Users/kpl/mambaforge/envs/qe/lib/python3.10/site-packages/jupyter_core/utils/__init__.py", line 166, in wrapped
   return loop.run_until_complete(inner)
   File "/Users/kpl/mambaforge/envs/qe/lib/python3.10/asyncio/base_events.py", line 649, in run_until_complete
   return future.result()
   File "/Users/kpl/mambaforge/envs/qe/lib/python3.10/site-packages/nbclient/client.py", line 1058, in async_execute_cell
   await self._check_raise_for_error(cell, cell_index, exec_reply)
   File "/Users/kpl/mambaforge/envs/qe/lib/python3.10/site-packages/nbclient/client.py", line 914, in _check_raise_for_error
   raise CellExecutionError.from_cell_and_msg(cell, exec_reply_content)
   nbclient.exceptions.CellExecutionError: An error occurred while executing the following cell:
   ------------------
   print("Hello Mojo")
   ------------------

----- stdout ----- Fontconfig warning: ignoring UTF-8: not a valid region tag ----- stderr ----- error: Execution was interrupted, reason: internal c++ exception breakpoint(-5).. The process has been left at the point where it was interrupted, use "thread return -x" to return to the state before expression evaluation.