agent-signals

037. Ctrl+C during a Codex turn opens a task dialog

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Date
2026-10-30
Agents
Codex CLI
Measured on
real machine

Measured

2026-10-30, Codex CLI 0.164.0 (standalone install, x86_64-unknown-linux-musl), on Linux (Debian 13, x64), in the default daemon mode, in a private tmux server with a throwaway HOME and a copied login. The scenario scenarios/codex/interrupt.sh recorded at each step the screen, the record types of the rollout file, and whether the TUI process ran. It read no content. Measured on: real machine.

The command was sleep 20, approved with the digit 1 on the approval dialog (--sandbox read-only --ask-for-approval on-request). On this machine bwrap cannot make a namespace, so a command in the sandbox fails at once ("bwrap: No permissions to create a new namespace ..."). With --ask-for-approval never, sleep 20 thus ended in less than 1 s with status 1. An approved command runs outside the sandbox.

What was measured

  1. Ctrl+C while the command ran did not stop the turn. It opened this dialog in place of the input box, with no busy line and no footer ? for shortcuts:

      Task is still running
  Choose what happens to the current task.


› 1. Cancel task        Stop the current task and stay in Codex
  2. Run in background  Exit Codex and leave the task running
  3. Exit               Stop the current task and exit Codex

  enter select · esc back

    The dialog added no record to the rollout file.

  2. The answers to the dialog. A digit acted at once, with no Enter.

    Key Screen Records added TUI
    1 (Cancel task) • Exited (status 1) sleep 20, ■ Conversation interrupted - use /feedback if something went wrong, the empty box custom_tool_call_output, token_count, message, turn_aborted runs
    Esc (back) the busy line • Working (7s • esc to interrupt) is back; the command ends (• Ran sleep 20) and the turn ends normally at the end: task_complete runs
    3 (Exit) no pane: the TUI exited custom_tool_call_output, token_count, message, turn_aborted exited

  3. Esc while the command ran (no dialog) gave the same screen and the same four records as 1. Cancel task, then one event_msg item_completed within 6 s. The TUI kept running.

  4. In an earlier run of the scenario, Ctrl+C came while the model wrote a long answer with no tool. The same dialog opened. The turn went on behind the dialog: the rollout file got task_complete and the Stop hook fired, and the dialog stayed open. Then the digit 2 of a typed prompt ("sleep 20") answered the dialog with 2. Run in background, and the TUI exited.

  5. Two Ctrl+C, 1 s apart, on an idle box exited the TUI in scenarios/codex/deny.sh and in the second run of scenarios/codex/daemon-life.sh. In the first run of daemon-life.sh, the same keys left two of three TUIs running.

Mechanism

Each interrupt that stops the turn writes turn_aborted: Esc during a command, 1. Cancel task, 3. Exit, and the denial of fact 36. A reader of the rollout file sees the end of the turn in each case.

A reader of the screen must know the dialog of item 1. It hides the busy line and the idle footer. A tool that types a prompt into it can answer it by mistake, because a digit acts at once (fact 4), and 2 exits the TUI.

Incident

The first version of the interrupt scenario typed a prompt with the digit 2 into this dialog. The TUI exited, and the scenario lost its pane.

Screens

codex/task-running-v0-164-0.

Not measured

Screens in the corpus that name this fact