Small tidbit so I could potentially find this later on: If you are running SonarQube yourself with the Community Edition (for a POC for example, otherwise invest in yourself by getting a higher edition!) then you might find this useful.
The default branch in SonarQube Community Edition is still locked to
master. If you want to change that in SonarQube then there is no user interface option available, as is in higher editions under Administration –> Branches and Pull Requests.
You can use this url to get to the same page for your project and change the name there:
https://sonarqube.server.url/project/branches?id=<your project name>