The previous commit introduced a counter leak in the backlog scan path:
handle_ci_exhaustion (without check_only) atomically incremented the CI
fix counter before the WAITING_PRS guard, so an exit 0 that never spawned
a dev-agent would silently consume one of the three allowed fix attempts.
Restore the READY_PR_FOR_INCREMENT / deferred-increment mechanism:
- Backlog scan calls handle_ci_exhaustion with "check_only" (read-only,
no increment) to detect exhaustion without touching the counter.
- The counter is bumped atomically at LAUNCH time via handle_ci_exhaustion
(without check_only), so the increment only happens when we are certain
a dev-agent is being spawned. If a concurrent poller already exhausted
the counter between scan and launch, the LAUNCH call returns 0 and we
bail out cleanly without double-spawning.
The in-progress, stuck-PR, and try_merge_or_rebase paths are unaffected:
they call handle_ci_exhaustion without check_only, which continues to use
the atomic ci_fix_check_and_increment to prevent concurrent double-spawning.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
4dc64ea65b