Codex CLI fails under Termux + proot Ubuntu on Android: `prctl(PR_SET_DUMPABLE, 0) failed` (0.42 works, 0.43+ broken)

What version of Codex is running?

codex-cli <paste output of codex --version here> In the same Termux + proot Ubuntu environment: - 0.42.0 works - 0.43+ fails with the PR_SET_DUMPABLE error described below

What subscription do you have?

ChatGPT Plus

Which model were you using?

Default (gpt-5.1-codex; the CLI exits with the error before I can change any model settings)

What platform is your computer?

Linux 6.1.134-android14-11-abX920XXU4CYJ4 aarch64 unknown

What issue are you seeing?

I’m running Codex CLI inside Termux on Android, using a proot-distro Ubuntu container on my Galaxy Tab S10 Ultra (arm64).

Up to Codex 0.42.0, everything works fine in this environment. However, from 0.43+ the CLI exits immediately with an error when I run even a simple command like:

codex --version

the error looks like this:
ERROR: prctl(PR_SET_DUMPABLE, 0) failed: No error information (os error 0)

So I can’t use Codex CLI at all on newer versions in this Termux + proot Ubuntu setup. I mainly use Codex like a chat assistant on my Android tablet, so this environment is important for me.

### What steps can reproduce the bug?


```markdown
1. On an Android arm64 device (Galaxy Tab S10 Ultra), install **Termux**.
2. In Termux, install `proot-distro` and set up an Ubuntu container, for example:
   ```bash
   pkg install proot-distro
   proot-distro install ubuntu
   proot-distro login ubuntu

3. Inside the Ubuntu proot container, install Codex CLI (for example via npm or the aarch64 Linux binary).


4. Run:

codex --version


5. On Codex 0.42.0 this prints the version and exits normally, but on 0.43+ it exits immediately with:

ERROR: prctl(PR_SET_DUMPABLE, 0) failed: No error information (os error 0)

### What is the expected behavior?

`codex --version` should behave the same way it does on Codex 0.42.0 in this environment:

- Print the version string (e.g. `codex-cli 0.xx.x`)
- Exit with status 0
- Allow me to continue using the CLI inside Termux + proot Ubuntu on Android

In other words, Codex CLI should not treat the `prctl(PR_SET_DUMPABLE, 0)` call as a fatal error under proot, or it should handle this environment more gracefully so that the CLI remains usable.

### Additional information

- This is a **regression**:  
  - Codex 0.42.0 works in exactly the same Termux + proot Ubuntu setup.  
  - Codex 0.43+ fails with the `PR_SET_DUMPABLE` error.
- Because of this, I have to pin Codex to `0.42.0` to keep using it on my Android tablet.
- I mostly use Codex as a chat-style assistant rather than for heavy coding, and Termux + proot is my main way to run Linux tools on Android.
- I’m happy to test any potential fixes or experimental builds on Termux/proot if that helps.