[Bug] Antigravity server crashed unexpectedly (SIGILL) on RDK X5 (Sunrise X5, Cortex-A55 ARM64) via Remote-SSH

Google Antigravity
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Bug Report: Antigravity Language Server Crashes with SIGILL on ARM Cortex-A55 (RDK X5 board) via Remote-SSH

Environment Details:

  • Antigravity version: 1.20.5 (commit 4603c2a412f8c7cca552ff00db91c3ee787016ff, date 2026-03-07T01:34:20.929Z)
  • Local OS: Windows 10
  • Remote device: D-Robotics RDK X5 board (Sunrise X5 SoC)
  • Remote OS: Ubuntu 22.04.5 LTS (jammy)
  • CPU: 8x Arm Cortex-A55 @1.5GHz (aarch64 / ARMv8-A)
  • RAM: ~7Gi total (6.9Gi shown in free -h)
  • Connection: Remote-SSH over local LAN (stable, official VS Code connects perfectly without any crash)

Symptom:

  • Remote-SSH connection succeeds, editor opens.
  • Shortly after, persistent error: “Antigravity server crashed unexpectedly. Please restart to fully restore AI features.”
  • Happens on every reconnect/restart.

Reproduction / Logs:
Language server starts but immediately exits with SIGILL:

From remote ~/.antigravity-server/…/*.log (key excerpts):
[13:09:24] (Antigravity) 2026-03-15 13:09:24 [INFO]: Language server killed with signal SIGILL
[13:09:24] (Antigravity) 2026-03-15 13:09:24 [ERROR]: Failed to start language server: Error: Language server exited before sending start data
[13:09:24] (Antigravity) 2026-03-15 13:09:24 [ERROR]: LS startLanguageServer error: Language server exited before sending start data
Repeated in later restarts (e.g., at 13:35:21, same SIGILL).

dmesg | grep -i “trap|sigill|illegal|invalid opcode” → no output (no kernel trap logged, but SIGILL is user-space CPU exception).

CPU features from /proc/cpuinfo | grep Features:
Features : fp asimd evtstrm crc32 atomics fphp asimdhp cpuid asimdrdm lrcpc dcpop asimddp

(This is ARMv8.0-A baseline + some ARMv8.1/8.2 like lrcpc/RCpc, asimddp/DotProd — missing advanced crypto like aes/sha3, or full SVE, RCPC2, etc.)

Root Cause Hypothesis:
The language_server_linux_arm (or arm64) binary is compiled with CPU features/extensions not supported on Cortex-A55 (e.g., ARMv8.3+ RCPC instructions like LDAPRB, or AES/crypto, or other optimizations in Go/BoringSSL/TCMalloc). This triggers immediate SIGILL (Illegal Instruction) on launch.

Similar issues reported on forum (e.g., SIGILL on ARMv8.2 servers missing RCPC, AES-NI on x86, TCMalloc VA issues on ARM64 Chromebooks/RPi). Official VS Code works because it doesn’t bundle the Antigravity-specific LS binary with these deps.

What I tried:

  • Cleaned ~/.antigravity-server multiple times
  • Settings: “remote.SSH.useFlock”: false, “remote.SSH.lockfilesInTmp”: true
  • Killed processes before reconnect
  • Official VS Code Remote-SSH → no issues (proves hardware/network ok)

Request:

  • Release a compatibility-focused ARM64 build targeting generic ARMv8.0-A / Cortex-A55 (no advanced extensions like RCPC2, full crypto, etc.)
  • Add runtime CPUID/feature detection in the LS binary to fallback or error gracefully
  • Workaround flag to disable LS (e.g., “antigravity.languageServer.enabled”: false) while keeping Agent features

Happy to provide strace/GDB on the binary, full cpuinfo, or test patched versions. This board (RDK X5) is popular for robotics/edge AI in China/Japan — better ARM support would be huge!

Thanks!