Unversioned files due to "?" folder automatically generated when compiling the git repo in a jenkins pipeline compiled in docker

Question

I am configuring Continuous Delivery with gradle using the gradle release plugin. This was working quite well using Travis CI. I am testing the same CD pipeline with Jenkins pipeline compiling everything in a docker container (gradle:4.7.0-jdk8). But I am receiving this error:

Execution failed for task ':t_gradle-release-example_release:checkCommitNeeded'.
> You have unversioned files:
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  ?? ?/
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Of course there is no such directory in the repo and it appears when compiling the repository. The repo is available in GitHub. As a workaround I removed the "?" folder (I can also include it in the .gitignore), but I need to know why this is happening in order to avoid the same issue in future pipelines.

UPDATE: It is happening to me also in GitLab. Any clue?

UPDATE 2: Inside the "?" folder there are three folders ".sonar",".gradle",".m2". Some volumes are shared between containers to cache dependencies. Could it be the reason?

Answer 1

This issue popped up in our build pipeline without any changes on our part.

We added ?/ to our .gitignore and this resolved the issue for us