Duplicate outputs from CLI
Resolved 💬 8 comments Opened Aug 29, 2025 by haonans Closed Oct 29, 2025
💡 Likely answer: A maintainer (etraut-openai, contributor)
responded on this thread — see the highlighted reply below.
What version of Codex is running?
codex-cli 0.27.0
Which model were you using?
Default, i believe gpt-5? I am a pro subscriber.
What platform is your computer?
Darwin 24.6.0 arm64 arm
What steps can reproduce the bug?
<img width="1464" height="228" alt="Image" src="https://github.com/user-attachments/assets/99f4efd3-58bf-4abe-9b50-ced6f6ec7274" />
I've been using the new codex heavily since released, it's amazing.
This issue happens not very often but I've seen a few times. IIRC, this happens usually when the line is a list item, and mostly the 1st list item.
Will add more details if I can consistently reproduce it.
What is the expected behavior?
_No response_
What do you see instead?
_No response_
Additional information
_No response_
8 Comments
<img width="1470" height="279" alt="Image" src="https://github.com/user-attachments/assets/7abe2f8a-01ce-47f6-ac69-ff2cf419bd7d" />
Again.
I think this is a problem with the LLM model itself, not the Codex
@piotrmaciejbednarski
It’s definitely Codex’s fault—the LLM model has nothing to do with it.
https://news.ycombinator.com/item?id=37543642
False.
A very valuable source of information. Very often, but it has never happened to me :) Inventing some kind of magic because someone can’t handle context—please provide me a link to a scientific article proving that such a problem exists in LLMs, because although it supposedly happens ‘very often’, it has never happened to me in any API.
Were you born yesterday? Do you know what a repetition penalty is?
@piotrmaciejbednarski
Yes, I know what repetition penalty is, and that makes repetition even less likely. Current models don’t repeat even at temperature 0. It’s an extremely rare, almost archaic case—I know this because I don’t think only in terms of yesterday, today, or tomorrow in this context. With Codex, however, it happened strikingly often, and if you had followed it, you’d know this problem is not new.
Please don’t take this as an attack — it’s just that there’s a problem in Codex with repeating output, and it would be great if this could be resolved. Honestly, in today’s world, repetition is almost an extreme.
Best regards
I think this issue is probably no longer relevant, so I'm going to close it. If you are still seeing this issue, let us know and I'll reopen.