The tool I’ve used forever doesnt work on Catalina (arg !)
Any recommendations ?
Versions ? Cornerstone ? or something else ?
I assume you want more than the built-in command line tool?
I don’t have any experience with SVN or it’s tools, but this Quora answer has a few suggestions, though it’s a little old.
Xcode doesnt include SVN tools any more so trying to issue the SVN command gets
svn: error: Failed to locate ‘svn’.
svn: error: The subversion command line tools are no longer provided by Xcode.
Such fun
I had a recommendation from Bob about SmartSVN which looks a lot like the tool I had used
I grabbed that and am back up and running
I have XVersion, but I find that I use the command line more than anything else (installed via homebrew).
I used to use the SVN client that was part of Oxygen XML (Synchro SVN), but in release 21 it was marked as “deprecated” so I started looking for replacements. XVersion was inexpensive enough for a self-funded open-source developer that I gave it a go.
My dev system is still on Mojave; not sure what I’ll have to change when I go to Catalina and beyond.
Syncro is the one I used for a long time 
I’m a bit late to the party, but as a macOS user I’ve been thrilled with Cornerstone and in particular really like the timeline view/feature. A year or two ago the indie company that created it, sold it off to Assembla, so I’m still on the last perpetual license version of 3.1. It’s now on version 4.x but I haven’t upgraded yet as it’s subscription based. If push comes to shove though, it might be worth $79 a year.
Second choice, or maybe first based upon pricing, would be Versions. It doesn’t feel as sophisticated as Cornerstone, but is still a perpetual license and feels a bit more Mac-like. The only minus here is that after the original devs, Made by Sofa, got acqui-hired by Facebook, they sold off their products to Black Pixel and Versions appears to mostly be in maintenance mode. At $59 for a perpetual license, it’s quite a bit cheaper for the long haul.
Both work just fine with Catalina and Cornerstone is almost a daily driver for me. Can’t really say if they work with Big Sur yet though as I’m yet to take the beta plunge.