Adding paths to the rysnc options will cause unexpected issues

I understand that `timemachine` expects only two arguments before the `--`-separated `rsync` options.

`timemachine` passes those "rsync options" after the `--` *as a whole* to `rsync`. This means that if those arguments contain one or more paths that `rsync` will accept, it will completely change the meaning of the generated `rsync` command-line, leading to unexpected behavior.

I don't think there's a way around this, apart from actually parsing the `rsync` options... 😱
(If only because they can be in either `--option=value` or `--option value` forms, forcing the tool to know them in accurate detail.)

No file, test, or entry point is named. Start by tracing how timemachine forwards arguments after the `--` separator into the generated `rsync` command, then define and verify behavior for options containing paths without changing the command's source or destination semantics.

Written by the indexing model from the issue text.