To summarize "virtualized" Catalina is working well, generally. For devs wishing to test drive XCode 11 beta, do a dual boot instead for now. I have installed it three times troubleshooting a crash issue when creating/opening a project within XCode 11 Beta in a VM on Catalina. While I have had no issues in with it in a dual boot scenario. I assumed that possibly Parallels tools was interfering... Conclusion, Xcode crashes when virtualized with or without Parallels tools.
Here is a summary of my experiences with each attempt.
1) I installed the first time, in a VM, I ran into a couple hangs using the following process: Install Mojave from recovery > Install Parallels tools > Install beta profile > Upgrade > Install XCode > (test/fail). This resulted in two hangs during upgrade (black screen with progress bar), where an "Action > Reset" would get things moving again. Discovered Xcode crashes.
2) I installed a second time, in a APFS volume, using the following process: Dual boot using a new APFS volume > Install Mojave from recovery > Install beta profile > Upgrade > Install Xcode > (test/success). No issues with the hangs or Xcode crashes.
3) Installed a third time, in a VM, using the following process: Install Mojave from recovery > Install beta profile > Upgrade > Install Xcode > (test/fail) > Install Parallels Tools. This process did not hang at all. The experience was sluggish without the benefits of Parallels tools, but presented no errors or hangs. Xcode still crashed without Parallels tools. Installing Parallels tools tells you it is "reinstalling" which it is not, and hangs at 100% when it should prompt to restart. Parallels tools installs fine regardless, you just need to manually reboot. Xcode still crashed with Parallels tools.
Notes:
- Drag and drop does not work unless you enable "Optimize for games" as mentioned in their Known Issues KB, but also note, that your mouse will stick to the edge of the screen requiring Ctrl+alt to release, which is annoying.
- Copy and paste between the host and guest doesn't work.
- Xcode crashes on project open/create with the stack trace failing at "Thread 0, com.apple.dt.SourceEditor MinimapMetalLinesLayer.defaultDevice() + 491. Assuming this may be related to new Apple Metal framework GPU changes not jiving with the Parallels hypervisor GPU. ¯\_(ツ)_/¯
Hoping to see a fix/workaround soon.