Assistant changed Codex install method during update without confirmation

Summary

When asked to update Codex to the latest version, the assistant attempted to update the local Codex CLI. After the update command failed with an installation-method detection error, the assistant proceeded to install a standalone user-level Codex binary under ~/.codex/packages/standalone and expose it through ~/.local/bin/codex, instead of asking before changing installation strategy.

Expected behavior

If the existing Codex binary is installed at /usr/bin/codex and the built-in updater cannot detect the install method, the assistant should stop and ask before using a different install method. It should either update the existing system binary in place with user-visible sudo approval, or explicitly ask whether a user-level standalone install is acceptable.

Actual behavior

The assistant installed Codex 0.135.0 as a standalone user install, created ~/.codex/packages/standalone, created ~/.local/bin/codex, added a PATH block to ~/.profile, and left /usr/bin/codex unchanged.

Impact

This created two Codex installations and changed PATH precedence, making the apparent update depend on shell resolution rather than properly updating the system install. It also wasted user time and tokens because the standalone install then had to be undone and replaced with a proper /usr/bin/codex update.

Root cause

The assistant treated making the latest codex resolve in PATH as equivalent to updating the existing installation. Changing installation method is a material system decision and should require confirmation.

Corrective action requested

When an updater cannot detect the install method, Codex should inspect the current binary location and ownership, identify the proper system-level replacement path, ask before changing install method, use a visible terminal or exact sudo command for root-owned paths, and verify that which codex still resolves to the intended system path after the update.

Final state after manual correction

The standalone install was removed, the PATH block was removed, /usr/bin/codex was updated in place to codex-cli 0.135.0, and a backup was created at /usr/bin/codex.0.130.0.bak.
GPT 5.5 Medium