[Bug]: Antigravity custom runtime fails local health check on Linux ARM64 (aarch64)

Before submitting

• I searched existing issues and did not find a duplicate.
• I included enough detail to reproduce or investigate the problem.

Area

apps/server

Steps to reproduce

1. Install the Antigravity runtime manually on a remote Linux server using the runtime package from Google's CDN.
2. Extract/install the runtime and verify that the runtime files are present on the server.
3. Open T3 Code and enable the Antigravity provider.
4. Configure Antigravity to use the custom binary/runtime path from the manual installation.
5. Attempt to use or authenticate the Antigravity provider.
6. Observe the provider status.

Expected behavior

T3 Code should detect and use the manually installed Antigravity runtime from the configured custom path.

If the runtime is valid and executable, the local health check should succeed and the Antigravity provider should become available.

Actual behavior

T3 Code reports the Antigravity provider as unavailable with:

"Antigravity could not complete its local health check."

The Runtime section shows the runtime as installed and indicates that the custom binary path is being used, but the provider remains unavailable.

Google sign-in also fails afterward, showing:

"Google sign-in failed. Start sign-in again."

Impact

Blocks work completely

Version or commit

v0.0.42

Environment

OS: Linux ARM64 (aarch64)

Logs or stack traces

Screenshots, recordings, or supporting files

Screenshot 2026-09-18 221605.png
Screenshot 2026-09-18 221554.png

Workaround

No workarround found

Start in apps/server by tracing how the configured custom Antigravity runtime path is used for the local health check on Linux ARM64. Reproduce with the manual runtime installation on v0.0.42 and inspect the health-check and sign-in failure behavior; done means the runtime is detected, the provider becomes available, and Google sign-in no longer fails.