Code coverage visualization in MR not working

I read Test coverage visualization. The documentation seems to be outdated as the suggested .gitlab-config.yml does not lint.

So I went to the plugin page and found a working config in the ReadMe that fits for my Java project. A target/site/coverage.xml is successfully generated, but no coverage is displayed in the MR. Here is my coverage.xml:

<coverage>
  <sources>
    <source>/builds/mygroup/mysubgroup/myproject/src/main/java/</source>
  </sources>
  <packages>
    <package name="com.mycorp.a.b.c>
      <classes>
         <class name="com.mycorp.a.b.c.Repository" filename="com/mycorp/a/b/c/Repository.java">
         [...]

Am I missing some configuration?

You need to tell GitLab where to find the coverage report. Add to your job:

artifacts:
    reports:
      coverage_report:
        coverage_format: <format>
        path: <path>