Codex on Windows intermittently aborts child processes as if Ctrl+C was pressed

[brownt12684]

What version of Codex CLI is running?

codex-cli 0.128.0

What subscription do you have?

Enterprise

Which model were you using?

gpt-5.4

What platform is your computer?

Windows

What terminal emulator and version are you using (if applicable)?

powershell

What issue are you seeing?

Environment:

• Windows
• PowerShell
• Repo/workdir: C:\Users\Travis\stack-orchestrator

Problem:
Codex’s local command runner intermittently aborts child processes as if Ctrl+C was pressed, even when I did not interrupt anything.

Observed behavior:

• Long-running or medium-running subprocesses get terminated unexpectedly.
• In Codex this shows up as tool calls returning aborted.
• From the user side it feels like Codex “just closes” or exits like Ctrl+C was pressed.
• The behavior is consistent with a Windows console control event / process-group teardown.
• Short commands usually still work fine.

Commands most affected:

• uv run ...
• .venv\Scripts\python.exe -m unittest ...
• longer Python invocations in general
• npm start
• Electron / other long-lived child processes
• nested PowerShell launch flows

Commands that usually still work:

• short file reads
• node --check ...
• PowerShell parse checks
• short one-shot shell commands

Concrete symptoms seen:

• Codex tool output says aborted
• Long-running validation commands die mid-run
• It behaves like an inherited console/process-group cancel on Windows
• In related app logs/processes, the behavior matches Ctrl+C-style termination rather than a normal app exception

Impact:

• Makes it unreliable to run test suites or keep local servers/GUI processes alive from inside Codex
• Forced a workaround where long-lived processes had to be launched detached and validated manually
• Prevented trustworthy end-to-end validation from within Codex even when syntax-level checks passed

Reproduction pattern:

1. Start Codex on Windows in PowerShell
2. Run one or more medium/long subprocess commands such as:
   • uv run --project ...
   • .venv\Scripts\python.exe -m unittest ...
   • npm start

What steps can reproduce the bug?

Uploaded thread: 019deb36-d269-7100-90dd-89b785f6e2d6

1. Start Codex on Windows in PowerShell
2. Run one or more medium/long subprocess commands such as:
   • uv run --project ...
   • .venv\Scripts\python.exe -m unittest ...
   • npm start

What is the expected behavior?

• Codex can launch child processes and they keep running until:
  • the command finishes normally
  • the command fails normally
  • or you explicitly interrupt/cancel it

Additional information

No response