Fails to export livescripts

[DavidRConnell]

I would like to automate building documentation by exporting livescripts to markdown for use with a static site generator. The export function requires a display (related to #51?) and therefore fails in CI.

I set up a build task makeDocs which only runs export on a GettingStarted.mlx.

The error is:

 ** Starting makeDocs
  ## -----------------------------------------------------------------------------
  ## Error occurred in 'makeDocs' and it did not run to completion.
  ##   Identifier: 'cefclient:webwindow:MissingDisplay'
  ##      Message: DISPLAY environment variable must be set to a valid X11 display.
  ##        Stack:

I'm working on an example toolbox to test out using github actions with toolboxes (https://github.com/DavidRConnell/githubaction-toolbox-mwe). The mlx is very simple and just prints a few numbers (no plotting). I can run the makeDocs build task locally with matlab -batch 'buildtool makeDocs'. When adding the -nodisplay flag it doesn't error but it does hang and never completes the task.

As a test, I tried setting the environment variable DISPLAY=:0.0 and got the error:

** Starting makeDocs
  ## -----------------------------------------------------------------------------
  ## Error occurred in 'makeDocs' and it did not run to completion.
  ##   Identifier: 'cefclient:webwindow:launchProcessFailed'
  ##      Message: MATLABWindow application failed to launch. Unable to launch the MATLABWindow application. The exit code was: 267

Anyway to export examples? Not sure why this would require a display.

[mcafaro]

Hi @DavidRConnell ,

You need to create a virtual display as shown in the example below. Copy the "Start virtual display" step and put it in your workflow before calling MATLAB to export your live scripts.

name: MATLAB Build
on: [push]
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      
      - name: Start virtual display
        run: |
          sudo apt-get install xvfb
          Xvfb :99 &
          echo "DISPLAY=:99" >> $GITHUB_ENV
        
      - name: Setup MATLAB
        uses: matlab-actions/setup-matlab@v2
        
      - name: Run MATLAB command
        uses: matlab-actions/run-command@v2
        with:
          command: export("sample.mlx");
          
      - uses: actions/upload-artifact@v4
        with:
          path: sample.pdf

We are looking at ways of removing the display requirement for exporting live scripts in the future.

Best,
Mark

[DavidRConnell]

That worked thank you.