Dry run `put` / debug exclusions

[piegamesde]

Thanks to all those XDG offenders (looking at you, Chromium and Electron :angry:), I have an extensive list of backup exclusions. I'd like to periodically check that I don't accidentally miss something important and that I don't include some random 3GiB cache. For this, some kind of "dry run" mode that simply walks over the file system and print the exclusions status would be helpful.

[dimitarvp]

I know this doesn't directly address your issue but you can get halfway there by using the --print-file-actions option of bupstash put and store the output in a file. Then you can query it for what was excluded and what was added to a snapshot.