GitLab decoration `ERROR: ... Caused by: Duplicate key []`

Hello there,

We’re using SonarQube 7.5, Scanner 3.3.0.1492, and Gitlab plugin 4.0.0

We are using SonarQube to analyze a swift project and the sonar-gitlab-plugin to send the report back to gitlab. We’ve been using SonarQube for a while and now in one of our feature branches, we have run into a strange issue. Here are the logs:

We have tried to run SonarQube Scanner using the -X switch, but no extra logs is provided where the failure happens.

The analysis is uploaded to the SonarQube server successfully, but the GitLab Commit Issue Publisher post job fails with that Duplicate code error.

This failure is only happening in one of our feature branches. When we make a new commit, analysis passes, however, as soon the commit messages are squashed the analysis fails with the above error.

Any help is appreciated.