Function analyze_input 

pub fn analyze_input(
    merge_args: &MergeArgs,
    input: AnalysisInput,
    progress: &dyn ProgressObserver,
    cancellation: &CancellationToken,
) -> Result<AnalysisView, String>

Run the complete N-way analysis foch merge runs for merge_args, over the inspected input. The browser never commits, so merge_args.out only names where a commit would have gone; it is a fresh path that analysis leaves untouched.