Hi,
The setting on the "Help" tab currently isn't updated by the MySQL Path field. The debug info on the Help tab is just whether or not Revisr automatically detected that item.
I can see now how that may be confusing and will be improving this area. But for now you should be able to just set the MySQL Path to /usr/bin/ and backups should work if that is the correct path and mysqldump is available.
Please feel free to let me know if you have any further questions. Thank you.