Looks like a new Xcode RC was recently released (15.3) so if you are set to use the latest release then you might be running into this issue. Xcode Cloud using that RC as the latest release. This happened to us once before. Switching to use a previously released version of Xcode (15.2, temporarily) seems to have fixed the issue for us.

I've also been seeing this for the last month and a half since we started using Xcode Cloud. I really want to use Xcode Cloud but we have lots of failed builds, probably one in 5-10, which is way to frequent. Seems like maybe Github is rate limiting the Xcode Cloud servers or something. What makes you think it would be a memory issue?