Graphviz dot files stopped being converted to png

[fniessink]

Recently, Graphviz dot files in the documentation of Quality-time (https://quality-time.readthedocs.io/en/latest/) stopped being converted to png images on RTD. Running sphinx locally works fine, and the dot files are converted to png as expected.

This version of the docs, created Jan 2, 2022, has the dot files converted: https://quality-time.readthedocs.io/en/v3.31.0-rc.4/software.html.

This version of the docs, created Jan 6, 2022, has the dot files not being converted: https://quality-time.readthedocs.io/en/v3.31.0-rc.5/software.html. Instead, the text of the dot file contents are displayed.

The only documentation-related dependency updated between these two dates in the Quality-time project was furo (bumped from 2021.11.23 to 2022.1.2), but reverting furo did not solve the issue.

Details

• Read the Docs project URL: https://readthedocs.org/projects/quality-time/
• Build URL (if applicable): https://readthedocs.org/projects/quality-time/builds/15701306/
• Read the Docs username (if applicable): fniessink

Expected Result

Graphviz dot files being converted to png and being displayed.

Docs with converted dot file: https://quality-time.readthedocs.io/en/v3.31.0-rc.4/software.html

Actual Result

The text of the dot file is shown instead of the png image.

Docs without conversion of dot file: https://quality-time.readthedocs.io/en/v3.31.0-rc.5/software.html

[stsewd]

Hi, looks like the config file was updated to make use of the new builder option ICTU/quality-time@cbfed80#diff-03efc769b870804394632e45d7885272b44c16939517fb31c9d7c614d2ffae57, the new builders don't include several pre-installed packages like the older ones, you must install them with https://docs.readthedocs.io/en/stable/config-file/v2.html#build-apt-packages. I think you only need to install the graphviz-dev and/or libgraphviz-dev packages.

[fniessink]

Thanks so much, installing graphviz did the trick. This is how the build part of the .readthedocs.yaml now looks:

build:
  os: ubuntu-20.04
  tools:
    python: "3.10"
  apt_packages:
    - graphviz