stanfordnlp/dspy

[Bug] ParallelEvaluate `causes cannot schedule new futures after shutdown on long evals`

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#9574 opened on Apr 7, 2026

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 (1 comment) (0 reactions) (0 assignees)Python (4,708 stars) (290 forks)batch import
help wanted

Description

dspy.Evaluate doesn't expose timeout. ParallelExecutor's 120s straggler timeout causes cannot schedule new futures after shutdown on long evals.

source: https://x.com/kargarisaac/status/2041596855172424159

Contributor guide

Tech stack
python
Domain
machine learningbackendtesting
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
PythonDSPyconcurrent.futures
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
35
Research direction
Examine the ParallelExecutor implementation in DSPy to understand the shutdown sequence and the 120 second straggler timeout. Modify the Evaluate class to expose a timeout parameter or prevent the 'cannot schedule new futures after shutdown' error. Check the referenced Twitter thread for additional context.