🤖 bench: simplify terminal-bench timeout handling #533
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…andling
**Root Cause:**
Agent was setting max_timeout_sec=float('inf') which bypassed terminal-bench's
timeout enforcement, causing tasks to hang indefinitely. Nov 8 nightly run hit
the 3-hour workflow timeout when tasks hung.
**Changes:**
1. **Critical Fix (cmux_agent.py):**
- Change max_timeout_sec from float('inf') to None
- Allows terminal-bench to properly enforce timeouts
- Prevents infinite task execution
2. **Defense-in-Depth Timeout Layers:**
- Terminal-bench: --global-agent-timeout-sec (configurable)
- Cmux agent: --timeout via CMUX_TIMEOUT_MS (Makefile exports)
- Shell: timeout command with 60s buffer (cmux-run.sh)
- Workflow: 240 min total timeout (up from 180 min)
3. **Nightly Configuration:**
- Aggressive 15-min per-task timeout (down from 30 min default)
- Faster detection of hung tasks
- Added task_timeout parameter to workflows
4. **Improved Monitoring:**
- Results summary shows pass rate percentage
- Detects and reports timeout-related failures
- Better error messages when results missing
**Testing:**
- Syntax validated (Python, Bash, YAML)
- Typecheck passes
- Formatting applied
Successful runs typically complete in ~60-90 minutes. The 4-hour workflow
timeout provides headroom for API slowdowns while preventing infinite hangs.
_Generated with `cmux`_
TerminalCommand requires max_timeout_sec to be a float, not None. By not setting it at all, we use the Pydantic default (180s) while still allowing terminal-bench's --global-agent-timeout-sec to take precedence.
Terminal-bench format uses .results[] not .trials[], and is_resolved not .resolved. Also improved output format to show failure_mode and avoid bc dependency.
Agent logs are saved as artifacts, so no need to spam console output. Changes: - Disable livestream by default (was true, now false) - Filter output to show only key info: task selection, timeouts, results - Save full benchmark.log as artifact for debugging - Show last 50 lines on error for quick diagnosis Console now shows: ✓ Configuration (dataset, timeout, sample size) ✓ Selected task IDs ✓ Results summary (resolved/unresolved/accuracy) ✗ Not shown: verbose agent logs, docker output, intermediate steps Full logs still available in benchmark.log artifact.
- Remove task_timeout input parameter (use TB default: 1800s) - Remove redundant shell-level timeout in cmux-run.sh - Simplify workflow output (full logs saved in artifacts) - Simplify results summary display - Change nightly livestream default: true -> false Net result: -2 LoC while maintaining functionality
ammario
approved these changes
Nov 8, 2025
ammar-agent
changed the title
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Problem
Nightly terminal-bench run hit 3-hour timeout. Root cause: agent set
max_timeout_sec=float('inf')which bypassed terminal-bench's timeout enforcement.Solution
Remove
max_timeout_sec=float('inf')to respect terminal-bench's global timeout. Simplified timeout handling and reduced complexity.Changes:
max_timeout_secin cmux_agent.pyNet: -2 LoC
Testing
Ran TB workflow dispatch with 3 tasks:
tmux-advanced-workflow)Generated with
cmux