manual install in [1].
It builds and pushes successfully the image.
But, currently the job fails at the end due to internal details of the plugins we are
not able to troubleshoot easily yet (see [2] [3]).
[1] https://jenkins.softwareheritage.org/job/wip-maven-indexer-exporter/
[2] https://jenkins.softwareheritage.org/job/wip-maven-indexer-exporter/92/console
[3] The stage 'push image' raises somehow a null pointer...
```
18:05:42 java.lang.NullPointerException: Cannot invoke method clone() on null object
```