[sir_eliah]

There's a cross-platform open-source version of this program: https://github.com/qarmin/czkawka

[nulld3v]

I don't think czkawa supports deduplication via reflink so it's not exactly the same thing. fclones as linked by another user is more similar: https://news.ycombinator.com/item?id=43173713

[spiderfarmer]

That’s not remotely comparable.