LucidDan

I used this to great success in 1.9.1 as well, thanks @whitespacekilla! Additional steps for 1.9.1: the naming of the development build from Unity 2019.2.2 is slightly different (macosx64_development_mono), and you need the UnityPlayer.dylib as well as (or possibly instead of?) the UnityPlayer binary. Also as noted by others for Linux and Windows, instead of PlayerConnectionConfigFile, this is now an entry in boot.config, which on the Mac app is stored in Contents/Resources/Data/, so: I tested with both Visual Studio for Mac (with Unity Tools) and JetBrains Rider, and I was able to attach a Unity debugger to the KSP process. I had mixed success with VS for Mac, but Rider worked perfectly - compiled and installed a copy of HyperEdit, set a breakpoint. Portable debug symbols worked out of the box, no pdb2mdb magic required. CPU load was through the roof for some reason, especially on the Main Menu, but otherwise, it worked quite well. Will definitely be keeping this around as a backup dev/debug setup for when I'm not at the desktop Windows rig.

@Neroziat you can use the Betas menu in Steam to access older versions. There is a "previous_1.0.5" and a "previous_1.1.3" to go back to those versions. Make sure you back up your save games and craft files etc beforehand.