Codex hang using ~99% CPU after thinking for a few seconds on long conversation

What version of Codex is running?

0.1.2504172351

Which model were you using?

03

What platform is your computer?

Darwin 24.3.0 arm64 arm

What steps can reproduce the bug?

Not sure the exact steps as this has only happened once so far.

After using codex for a while (in full auto mode), when I sent a new prompt it "thought" for around 16s then the terminal stopped updating. Looking in Activity Monitor, the process was stuck using between 98 and 99% CPU. I waited for a few minutes but the terminal UI was still frozen and the process stuck at 99% CPU.

What is the expected behavior?

_No response_

What do you see instead?

_No response_

Additional information

This was running in an Apple Silicon macOS VM on macOS 15.3.2. I had been using it for around 15 minutes when the issue occurred. The working directory was a simple web app with less than 10 files and the largest file is 150 lines long.

Attached is a process sample taken at the time the process was in that state.

Sample of codex.txt