[Marukome0743]

Summary

• isolate non-interactive macOS task commands in a new session when mise is attached to a terminal
• preserve process-group-based descendant cleanup and existing interactive/raw task behavior
• add a macOS tmux regression test for zsh process substitution and run it in CI

Root cause

PR #9655 placed parallel task commands in independent process groups so failure and interrupt cleanup could terminate their full process trees. On macOS, a non-interactive zsh command in that process group can still interact with tmux's controlling terminal during process substitution and become job-control stopped. Linux does not exhibit the same behavior, and the macOS reproduction also completes with --jobs 1 or when mise's process-group management is disabled.

For non-interactive commands launched under a macOS terminal, this change uses setsid() instead. The child remains the leader of a process group whose ID matches its PID, so the existing killpg(child_pid) cleanup continues to reach descendants without leaving zsh attached to tmux's controlling terminal.

Verification

• mise exec -- cargo test --all-features cmd::tests::test_child_process_isolation
• mise run test:e2e e2e/tasks/test_task_zsh_process_substitution_tmux_macos
• mise run test:e2e e2e/tasks/test_task_parallel_fail_fast
• mise exec -- cargo check --all-features
• mise exec -- cargo clippy --workspace --all-features --all-targets -- -D warnings
• mise exec -- cargo fmt --all -- --check
• mise exec -- shellcheck e2e/tasks/test_task_zsh_process_substitution_tmux_macos
• mise exec -- shfmt -d e2e/tasks/test_task_zsh_process_substitution_tmux_macos

Addresses #9790

AI-assisted — Tool: Codex; model: OpenAI/GPT-5; version: unavailable.

Summary by CodeRabbit

• Bug Fixes

  • Improved process handling on Unix systems, including macOS, for more reliable task execution and isolation.
  • Fixed edge cases involving zsh process substitution when running tasks inside tmux.
  • Improved behavior for both synchronous and asynchronous task execution.

• Tests

  • Added macOS end-to-end coverage for parallel tasks, process substitution, and tmux-based execution.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Repository YAML (base), Central YAML (inherited), Organization UI (inherited)

Review profile: CHILL

Plan: Pro Plus

Run ID: 2b633165-48f3-47bb-ae5f-b0d1810f11b1

📥 Commits

Reviewing files that changed from the base of the PR and between 34f27d8 and 242111f.

📒 Files selected for processing (1)

• e2e/tasks/test_task_zsh_process_substitution_tmux_macos

🚧 Files skipped from review as they are similar to previous changes (1)

• e2e/tasks/test_task_zsh_process_substitution_tmux_macos

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📝 Walkthrough

Walkthrough

The change centralizes Unix child-process isolation for synchronous and asynchronous execution. It adds unit tests for isolation selection and a macOS tmux end-to-end test for zsh process substitution.

Changes

Process isolation and regression coverage

Layer / File(s)	Summary
Unified child isolation setup src/cmd.rs	prepare_execute_child selects inherited groups, process groups, or macOS sessions. Synchronous and asynchronous execution use the helper. Unix tests cover the selection behavior.
macOS tmux regression test .github/workflows/test.yml, e2e/tasks/test_task_zsh_process_substitution_tmux_macos	The macOS job installs fd and tmux, then runs a zsh process-substitution test with parallel tasks, status checks, output validation, and cleanup.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Sequence Diagram(s)

sequenceDiagram
  participant Workflow as macOS workflow
  participant Tmux as tmux
  participant Mise as mise task runner
  participant Zsh as zsh process substitution
  Workflow->>Tmux: Start detached test session
  Tmux->>Mise: Run aggregate task with parallel jobs
  Mise->>Zsh: Execute process-substitution task
  Mise-->>Tmux: Write status and task output
  Tmux-->>Workflow: Provide completion status and logs

Loading

Poem

A rabbit watched the child groups align,
While tmux kept zsh processes in line.
Tasks ran side by side,
Status files opened wide,
And macOS tests made the output shine.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main change: preventing zsh process substitution hangs in task execution.

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[github-actions]

This PR currently has failing checks. If this continues for 7 days, it will be closed automatically.

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[greptile-apps]

Greptile Summary

The PR changes macOS non-interactive task execution to use a separate session when mise is attached to a terminal, preserving existing process-group cleanup and interactive behavior.

• Centralizes Unix child-isolation selection for synchronous and asynchronous commands.
• Adds a macOS tmux regression test for zsh process substitution.
• Installs tmux and runs the regression test in macOS CI.

Confidence Score: 5/5

The PR appears safe to merge.

No blocking failure remains.

Important Files Changed

Filename	Overview
src/cmd.rs	Introduces shared child-isolation logic that selects inherited terminal behavior, a process group, or a new macOS session.
e2e/tasks/test_task_zsh_process_substitution_tmux_macos	Adds isolated macOS regression coverage for parallel zsh process substitution under tmux; the previously reported redundant temporary-file deletion is no longer present.
.github/workflows/test.yml	Installs tmux in the macOS test job and executes the new regression test.

_{Reviews (4): Last reviewed commit: "fix(task): avoid zsh process substitutio..." | Re-trigger Greptile}