Nice job.

I'm a little skeptical though -- I think the devil is in the details. It's a lot of work to make a highly reliable backup program. As a Windows user, here's a list of questions I'd ask:

1. Does Relica work with OneDrive on-demand files? [1]

2. Does Relica work with WSL files? [2]

Supporting all these corner cases on Windows, Mac, and Linux will be a TON of work.

[1]: https://support.office.com/en-us/article/learn-about-onedriv...

[2]: https://blogs.msdn.microsoft.com/wsl/2016/06/15/wsl-file-sys...