Fixing Google Antigravity IDE Agent crashing immediately on Proxmox

While in my day job I use Cursor, I’ve been trying out Google Antigravity for my personal projects, mainly due to the generous Gemini limits they provide via Google One (which I already pay for separately).

After trying it out on my beefy physical machine with secure mode enabled to make sure it doesn’t wipe my entire hard drive by mistake, I realised that I could trust it in a more hands-off fashion if I gave it its own playground.

I quickly setup a VM on my Proxmox node but as soon as I attempted to connect to my VM via the SSH extension I would get this error:

Antigravity server crashed unexpectedly. Please restart to fully restore AI features.

No other info unfortunately. A restart would lead to the same behaivor immediately. I tried looking into the Antigravity logs but I didn’t find anything useful.

Eventually with some googling I found a Reddit thread which, while the issue there was Mac specific, had the answer for buried deep in a comment. I’m recreating it here to hopefully make it easier for the next person to solve.

Checking a different part of Antigravity error logs revealed the following: FATAL ERROR: This binary was compiled with pclmul enabled, but this feature is not available on this processor (go/sigill-fail-fast)..

The solution on Reddit provided by user ConKernel was: If using proxmox VM, try changing host processor to "host" and reboot the VM. It worked for me

This I can confirm also worked for me and now I can use Antigravity SSHed into my Proxmox VM just fine.