Sage documentation links in help menu have been long broken in jupyterlab notebook interface, although they work fine in jupyter notebook interface.

Jupyterlab loads local files (sage documentation files) in iframe tag. This is problematic and it seems hopeless to make this work. A proper way is to run local http server serving the doc along with jupyter(lab) notebook server.

The branch uses thread parallelism to run sage doc server.

Try the branch with sage --notebook=jupyterlab. This runs a light-weight sage doc server at http://localhost:<SAGE_DOC_LOCAL_PORT>, where the environment variable SAGE_DOC_LOCAL_PORT defaults to 8000.

Set export SAGE_DOC_SERVER_URL=https://doc.sagemath.org before running sage --notebook=jupyterlab to use the public doc server. This will be useful for jupyterhub users.

Component: notebook

Author: Kwankyu Lee

Branch/Commit: public/run_doc_server @ 70bdf46

Issue created by migration from https://trac.sagemath.org/ticket/34794