There is a bug in Apple’s hypervisor framework that can cause issues in virtualized environments like ours. The issue can occur whenever a simulator is launched: for example, our Xcode Test for iOS Step uses an iOS simulator to run tests. Once the simulator starts, your build can hang indefinitely. The issue has already been reported to Apple, under the following ID: FB10015465.
In order to confirm that you are having this issue, we recommend running the following command: sudo dmesg
It is really hard to predict if a build will produce the issue in order to build it we remote access in order to execute this command, is there a way you used to execute this command sudo dmesg during build ?
Since it’s pretty reliably reproducible for us, I was able to enable remote access and run sudo dmesg while it was hung. I did get a GPU hang as referenced above; here’s the full report if that’s helpful: