Snapshot git index.lock blocks LLM responses for 60+ seconds after crash #28952

Symptoms

• OpenCode appears to "spin" with no response for 60+ seconds
• All models seem unresponsive (no streaming, no thinking process shown)
• Eventually a response comes back, but subsequent responses also lag
• No error messages shown to the user in the UI
• Only visible in logs: repeated snapshot-related errors with git lock failures

Root Cause

OpenCode's snapshot service uses a local git repository at:

~/.local/share/opencode/snapshot/global/<hash>/

When an OpenCode session crashes unexpectedly (force close, system reboot, process kill), the git repository can be left with a stale index.lock file:

~/.local/share/opencode/snapshot/global/<hash>/.git/index.lock

On the next startup, every snapshot file-change operation tries to acquire the git lock, times out after ~30-40 seconds, and accumulates across multiple snapshot attempts. Since LLM streaming waits on snapshot operations, the total delay before the first token appears can exceed 60 seconds.

Log evidence:

ERROR SnapshotError: Failed to execute git command
Caused by: Unable to create '<path>/.git/index.lock': File exists.

Steps to Reproduce

1. Start OpenCode and use it normally
2. Force-kill the OpenCode process (or crash the system)
3. Restart OpenCode and send a message
4. Observe 60+ second delay before any response
5. Check ~/.local/share/opencode/log/ for snapshot-related errors

Workaround

Delete the stale git repository:

rm -rf ~/.local/share/opencode/snapshot/global/*/

OpenCode will recreate it on the next file change.

Or more selectively, just remove the lock file:

rm -f ~/.local/share/opencode/snapshot/global/*/.git/index.lock

Suggested Fix

The snapshot service should:

1. Detect and automatically clean up stale index.lock files on startup (git lock files older than the process lifetime are always stale)
2. Or use a short timeout for lock acquisition and fall back gracefully instead of blocking
3. Or at minimum surface a warning to the user when snapshot operations are blocked

Environment

• OpenCode version: 1.15.10
• Platform: Windows 11
• Client: CLI (opencode)