codex 0.125.0 (Homebrew cask) hangs on startup on macOS — no TUI, no output, no error

Summary

After Homebrew auto-bumped the codex cask to 0.125.0 today, running codex
with no arguments hangs indefinitely. There is no TUI, no stdout/stderr output,
and no error. The process has to be killed manually. Even codex --version
hangs, so this is not a TUI-only problem — the process never gets far enough to
print its version.

Environment

• codex (Homebrew cask): 0.125.0 (/opt/homebrew/bin/codex →

/opt/homebrew/Caskroom/codex/0.125.0/codex-aarch64-apple-darwin)

• macOS: 26.4.1 (build 25E253), arm64 (Apple Silicon)
• Codex desktop app also installed at \/Applications/Codex.app\, version

bundle 26.422.62136, bundling CLI 0.126.0-alpha.8. The desktop app
was running at the time of the hang, with an \app-server\ process and an IPC
socket at \\$TMPDIR/codex-ipc/ipc-502.sock\.

Reproduction

1. Have the Codex desktop app running (its \app-server\ is active and the IPC

socket exists in \\$TMPDIR/codex-ipc/\).

1. Run \codex\ (no args) from a normal terminal.
2. Process hangs forever; needs SIGKILL/Ctrl-C to exit.
3. \codex --version\ also hangs (no output before the hang).

What works

• \/Applications/Codex.app/Contents/Resources/codex --version\ (the

desktop-app-bundled CLI, 0.126.0-alpha.8) responds immediately.

• So this appears to be specific to the standalone Homebrew-cask CLI 0.125.0.

Hypothesis

Possibly a version mismatch between the standalone CLI (0.125.0) and the
desktop app's app-server / IPC socket (0.126.0-alpha.8) leads to a handshake
that never completes, with no timeout or error path. But since \--version\
hangs too, the issue is hit very early in startup — before any TUI work — so
the cause may be more general (e.g. blocking IPC/auth/marketplace probe with
no timeout).

Notes

• Binary is signed (TeamID \2DC432GLL2\). Has the usual \com.apple.quarantine\

xattr from a Homebrew cask install — Gatekeeper would surface a dialog, not
silently hang, so I don't think that's it.

• \~/.codex/config.toml\ contains a couple of values that look non-standard

(\model = \"gpt-5.5\"\, \model_reasoning_effort = \"xhigh\"\,
\personality = \"pragmatic\"\); willing to retest with those removed if it
would help triage.