**Headless mode:** `gsd headless auto` auto-restarts the entire process on crash (default 3 attempts with exponential backoff). Combined with provider error auto-resume, this enables true overnight unattended execution.
**Symptoms:** Auto mode pauses with "Budget ceiling reached."
**Fix:** Increase `budget_ceiling` in preferences, or switch to `budget` token profile to reduce per-unit cost, then resume with `/gsd auto`.
### Stale lock file
**Symptoms:** Auto mode won't start, says another session is running.
**Fix:** If no other session is actually running, delete `.gsd/auto.lock` manually. GSD includes stale lock detection (checks if the PID is still alive), but edge cases exist.
### Git merge conflicts
**Symptoms:** Worktree merge fails on `.gsd/` files.
**Fix:** GSD auto-resolves conflicts on `.gsd/` runtime files. For content conflicts in code files, the LLM is given an opportunity to resolve them via a fix-merge session. If that fails, manual resolution is needed.
## Recovery Procedures
### Reset auto mode state
```bash
rm .gsd/auto.lock
rm .gsd/completed-units.json
```
Then `/gsd auto` to restart from current disk state.
### Reset routing history
If adaptive model routing is producing bad results, clear the routing history:
```bash
rm .gsd/routing-history.json
```
### Full state rebuild
```
/gsd doctor
```
Doctor rebuilds `STATE.md` from plan and roadmap files on disk and fixes detected inconsistencies.