Editor Memory Leak related to GI Cache trim disk job

Posting this in the hope that this helps preserve someone else's hair...

TLDR; Massive Editor memory leak after doing some light map baking? Try clearing the GI Cache (Preferences -> GI Cache -> Clean Cache)

Long Story Version:

I ran into a confounding memory leak in the Editor in my project where Unity would gobble up about 4MB a second until of course I quit or it consumed all of my system's memory. Very frustrating. Working with the memory profiler didn't suss out anything I could make sense of.

Problem started in 2019.3; I upgraded to project to 2019.4 and it persisted. Cleared Library, reloaded project problem persisted. Rolled project back in VC many steps to where I was certain it hadn't been leaking before -- problem persists. Weirdly though, running the same project on my MBP resulted in no memory leak. All along I had a hunch that the problem had something to do with Lightmapping, as that when it seemed to start; in fact I had a similar memory leak earlier after doing a bake on a large scene and leaving my machine unattended but in that case after fumbling around I managed to make it go away.

Finally the bright idea dawned on me to see what was happening in the console -- clearly some process was going rogue. Sure enough: this message was being printed over and over:

TrimDiskCacheJob: Current cache size 11575mb

LocalFileCache size was not reduced below threshold at path: /Users/bo/Library/Caches/com.unity3d.UnityEditor/GiCache. ( 12137520064 / 10737418240)

Googling around on TrimDiskCacheJob tells me it has something to do with the GI Cache. Aha! I hit "Clean Cache" and the leak stops. Happy Dance.

 

Thank you for confirming this! The same thing happened to me. I'd say this is a bug worth filing...