Possible orphaned Python subprocess leak in Codex Desktop on macOS (Apple Silicon)

Environment

• Platform: macOS Apple Silicon
• App: Codex Desktop
• Python installed via Homebrew
• Observed date: May 2026

Observed behavior

After using Codex Desktop, I found a Python process continuing to run indefinitely even after the originating terminal/session appeared closed.

The process:

• remained alive with PPID = 1
• consumed ~99% CPU continuously
• persisted independently from the original shell session
• appeared to be reading from stdin rather than executing a normal .py file

Evidence

Process list:

bash ps -Ao pid,ppid,pcpu,pmem,comm | sort -k3 -nr | head -20

Relevant output:

text 65600 1 98.8 0.0 …/Python

Command inspection:

bash ps -wwp 65600 -o command=

Output:

text /opt/homebrew/…/Python -

The trailing - suggests Python was launched using stdin piping/heredoc style execution rather than a standalone script.

Open files:

bash lsof -p 65600 | head -50

Relevant findings:

text cwd: /Users/…/Education/Physics/Nanoscience/Assignments stdin: /private/tmp/zshfhR7eo

This suggests:

• stdin-fed shell execution
• temporary zsh-backed input
• orphaned subprocess after parent shell exited

Why this looks Codex-related

I found several existing reports describing similar process lifecycle issues:

• orphaned child processes
• subprocesses surviving terminal closure
• PPID reassignment to 1
• lingering high CPU usage
• pipe deadlocks / process-group cleanup failures

Examples:

• #14962
• #7846
• #7932
• #13928

Suspected root cause

This appears consistent with:

• subprocess group cleanup failure
• missing signal propagation
• or child processes not being reaped correctly after Codex task execution

Potentially related to:

• stdin-fed execution wrappers
• temporary shell pipes
• sandbox or process-group handling

Impact

Effects observed:

• sustained high CPU usage
• orphaned processes surviving session exit
• difficult-to-identify background execution
• potential battery/thermal drain on laptops

Recommendation

Possible mitigations:

• ensure subprocesses are attached to process groups
• propagate termination signals to descendants
• explicit child reaping on session/task completion
• cleanup of stdin-fed helper interpreters

Would be useful if Codex exposed:

• task → subprocess mapping
• cleanup logs
• process lifecycle diagnostics
• automatic orphan detection