[Bug]: Antigravity provider fails with "authenticated, but could not initialize a session or load models" on Windows #27193

Before submitting

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

Area

apps/web

Steps to reproduce

Signing in to the Antigravity provider completes Google OAuth, but immediately fails during session/new with JSON-RPC -32603 (Internal error), surfacing:

Antigravity authenticated, but could not initialize a session or load models.

Expected behavior

A smooth sign-in to antigravity accounts on windows

Actual behavior

When preparing the isolated Antigravity profile (GEMINI_CLI_HOME), linkAntigravityUserSkills in apps/server/src/provider/antigravityAuthSupport.ts creates symlinks (or NTFS junctions on Windows) pointing
to:

• ~/.gemini/config/skills
• ~/.gemini/antigravity-cli/skills

However, it creates those links without checking whether the target folders in ~/.gemini actually exist. If a user does not have those folders in ~/.gemini, the links in the profile point to non-existent
paths (broken symlinks/junctions).

When session/new runs, agy_acp_server calls os.makedirs(..., exist_ok=True) on the profile's skill paths. Because a broken link already occupies the path (os.mkdir fails with FileExistsError) and does
not resolve to a valid directory (os.path.isdir returns False, so exist_ok=True does not suppress the error), agy_acp_server crashes with FileExistsError ([WinError 183] on Windows / [Errno 17] on
POSIX).

Impact

Blocks work completely

Version or commit

0.1.5

Environment

Windows, Desktop App v0.1.5, Node v24.22.1, Antigravity

Logs or stack traces

Screenshots, recordings, or supporting files

No response

Workaround

The workaround was to clone this project, figure out why I couldn't activate the provider then manually create the missing skill folders for Antigravity sign-in to work on windows.