How to set up coverage reporting for project in subdirectory


I would like to set up test coverage integration. I have tried to follow the documentation at Test coverage visualization | GitLab I am running on

Inside the CI I run the tests similar to this:

    - docker run --name $CONTAINER_NAME $IMAGE_NAME python3 -m pytest --cov=/path/to/project/path/to/main/package --cov-report=xml:/app/coverage.xml /path/to/project/path/to/tests/package --junit-xml=/app/pytest.xml
    - docker cp $CONTAINER_NAME:/app/pytest.xml pytest.xml
    - docker cp $CONTAINER_NAME:/app/coverage.xml coverage.xml
    - sed -i "s|<source>/path/to/project/path/to/main/package</source>|<source>${CI_PROJECT_DIR}/path/to/main/package</source>|" coverage.xml
    - cat coverage.xml
      junit: pytest.xml
        coverage_format: cobertura
        path: coverage.xml

In the cat output I can see that the source is now

The relative paths in the filename fields are correct paths to the files from the source path. I have confirmed the source path is correct with ls.

At the end of the build is the message:

Uploading artifacts...
coverage.xml: found 1 matching files and directories 
Uploading artifacts as "cobertura" to coordinator... 201 Created  id=2638001478 responseStatus=201 Created token=hxygqbDC

Information about a changed file in the commit is mentioned in the coverage.xml.

I do not see any noticeable changes to the commit information report in GitLab. I am not sure what to try next for debugging.

Thank you for your help.