`nbconvert` not installed in deepnote

[bernhardpg]

Running a notebook in Deepnote that requires Grader from manipulation.exercises.grader will throw an error saying that nbconvert is not installed (manipulation.exercises.grader imports `nbconvert here).

nbconvert is listed as an optional dependency, and the current Docker workflow installs manipulation[all], so nbconvert should be installed to Deepnote.

For now we have implemented the following workaround:

Install nbconvert in the Init notebook that runs when the machine on Deepnote is started: notebook.

[bernhardpg]

See RussTedrake/htmlbook#19
@RussTedrake

[RussTedrake-walden]

One experiment we did tonight:

• open a terminal on deepnote. it automatically opens in the root/venv activated. run pip freeze. We see nbconvert is installed.
• running pip install nbconvert in the terminal installs nothing
• navigate back to a notebook, and try to import the manipulation grader, it fails with "nbconvert is not installed".
• run !pip freeze in the notebook, and see that nbconvert is missing.
• run !pip install nbconvert in the notebook, and the issue is resolved. Note that it installs a few additional packages, too.

So the question is... why does the system-installed nbconvert not make it into the notebook's environment? I suspect there is some dependent library that has a version mismatch (perhaps jupyter or jedi, since they have had special treatment in deepnote in the past), which causes dynamic loading of nbconvert to fail. I suspect if we get the versions to all line up, then things will work again, but we haven't gone through the effort yet. And it's feels potentially brittle to do so.