We would like to move forward with deprecating the label master for our default development branches in projects ( per T254646, T281593, T279612, T377562 ), but the efforts to change the default branch name on all repositories in gerrit has floundered because of concerns about:

• confusing developers - if we have projects in gerrit with a mixture of master and main default branches, it will be more confusing for developers to work with and contribute to the projects
• breaking our toolchain - we don't know in how many places what parts of our gerrit toolchain have a hard-coded expectation that the default development branch is called main.

Rename the default branch in WikibaseLexeme from master to main, and create a git symbolic reference from main to master to ensure a smoother experience for developers. See what parts of the toolchain break, or what issues (if any) arise.