doc: Remove Sphinx theme and extensions from the repository

[seisman]

Description of proposed changes

Changes in this PR:

• Remove the local Sphinx theme
• Remove the local Sphinx extensions
• Replace the deprecated sphinx-panels extension with the sphinx-design extension
• List all doc dependencies in doc/rst/requirements.txt
• Improve the "Docs" workflow

To build the GMT documentation, you need to install the Sphinx theme and extensions. This can be done using the following command:

pip install -r doc/rst/requirements.txt

Closes #7847

[PaulWessel]

I tried the sequence of commands on the Documentation contribution page. Since I now need some sphinx stuff irst I did

pip install -r doc/rst/requirements.txt

then

dvc pull
cmake --build . --target docs_depends     # Generate images included in the documentation
cmake --build . --target optimize_images  # Optimize PNG images for documentation [optional]
cmake --build . --target docs_man         # Build UNIX manual pages
cmake --build . --target docs_html        # Build HTML manual, tutorial, cookbook, and API reference

but during the docs_man I get this

[7/7] Building manpages...
FAILED: doc/rst/CMakeFiles/docs_man /Users/pwessel/UH/RESEARCH/CVSPROJECTS/GMTdev/gmt-dev/rbuild/doc/rst/CMakeFiles/docs_man 
cd /Users/pwessel/UH/RESEARCH/CVSPROJECTS/GMTdev/gmt-dev/rbuild/doc/rst && /opt/local/bin/sphinx-build -q -b man -c /Users/pwessel/UH/RESEARCH/CVSPROJECTS/GMTdev/gmt-dev/rbuild/doc/rst -d /Users/pwessel/UH/RESEARCH/CVSPROJECTS/GMTdev/gmt-dev/rbuild/doc/rst/_doctrees_man -t nosphinxdesign /Users/pwessel/UH/RESEARCH/CVSPROJECTS/GMTdev/gmt-dev/rbuild/doc/rst/source /Users/pwessel/UH/RESEARCH/CVSPROJECTS/GMTdev/gmt-dev/rbuild/doc/rst/man 2> /Users/pwessel/UH/RESEARCH/CVSPROJECTS/GMTdev/gmt-dev/rbuild/doc/rst/man.log && /usr/bin/gzip -9 -n -f /Users/pwessel/UH/RESEARCH/CVSPROJECTS/GMTdev/gmt-dev/rbuild/doc/rst/man/*.?
ninja: build stopped: subcommand failed.

What do I do?

[seisman]

What are the error messages in /Users/pwessel/UH/RESEARCH/CVSPROJECTS/GMTdev/gmt-dev/rbuild/doc/rst/man.log?

[PaulWessel]

Extension error:
Could not import extension sphinx_copybutton (exception: No module named 'sphinx_copybutton')

[seisman]

What's the output for you?

$ which python
$ which pip

[PaulWessel]

which python
/Users/pwessel/miniconda3/bin/python
which pip
/Users/pwessel/miniconda3/bin/pip

They may be too old? I never use conda/miniconda so not sure how to update if that is required.

[seisman]

They should be fine. Maybe try:

python -m pip install -r doc/rst/requirements.txt

[seisman]

What's the output of which sphinx-build? It's likely that you installed Sphinx from Homebrew or MacPorts.

[PaulWessel]

which sphinx-build
/Users/pwessel/miniconda3/bin/sphinx-build

echo $PATH
/Users/pwessel/miniconda3/bin:/Users/pwessel/miniconda3/condabin:/opt/local/bin:/opt/local/sbin:/Library/TeX/texbin:/opt/homebrew/opt/sphinx-doc/bin:.:/Users/pwessel/bin:/Users/pwessel/miniconda3/bin:/Users/pwessel/UH/RESOURCES/SOFTWARE/bin:/Users/pwessel/binptr:/usr/local/bin:/System/Cryptexes/App/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/local/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/appleinternal/bin:/opt/X11/bin:/Library/Apple/usr/bin:/Library/TeX/texbin:/usr/X11R6/bin:/Users/pwessel/GMTdev/mbsystem/bin:/opt/homebrew/bin

so I also have /opt/local/bin/sphinx-build

[seisman]

It's likely that cmake found this one /opt/local/bin/sphinx-build.

When you run cmake .. -G Ninja, at the end of output, you'll see the Sphinx path:

-- Found Sphinx: /home/seisman/opt/miniconda/bin/sphinx-build

[PaulWessel]

-- Found Sphinx: /Users/pwessel/miniconda3/bin/sphinx-build

[PaulWessel]

Hm, works now, possibly the PR you did last night on the requirements.txt?

[seisman]

Good to know it works. The changes I did last night are unrelated.