`/codex:setup` reports npm and codex as "Missing" / "Not installed" on Windows (Claude Code + Git Bash)

[masayan-kazu]

Environment

• OS: Windows 11
• Shell: Git Bash (mingw64) — used internally by Claude Code CLI
• Node.js: v25.8.1
• npm: 11.8.0
• Codex CLI: 0.117.0 (installed globally via npm install -g @openai/codex)
• Plugin version: 1.0.0

Problem

Running /codex:setup in Claude Code CLI reports:

Component	Status	Detail
Node.js	Available	v25.8.1
npm	Missing	not found
Codex CLI	Not installed	not found

However, all three binaries are correctly installed and accessible from the same shell:

$ which node
/c/Program Files/nodejs/node
 
$ which npm
/c/Program Files/nodejs/npm
 
$ which codex
/c/Users/xyz/AppData/Roaming/npm/codex

Root Cause

binaryAvailable() in scripts/lib/process.mjs uses spawnSync(command, args) without shell: true.

On Windows, npm and codex are installed as .cmd batch file wrappers (e.g., npm.cmd, codex.cmd). Node.js spawnSync without shell: true cannot resolve .cmd extensions, returning ENOENT.

node.exe works because it is a native .exe file, which spawnSync can resolve directly without a shell.

Proof

// FAILS — ENOENT (current plugin behavior)
const r1 = spawnSync('npm', ['--version'], { encoding: 'utf8' });
// r1.error.code === 'ENOENT', r1.stdout === undefined
 
// WORKS — returns "11.8.0"
const r2 = spawnSync('npm', ['--version'], { encoding: 'utf8', shell: true });
// r2.error === null, r2.stdout === "11.8.0\n"

Proposed Fix

Two changes in scripts/lib/process.mjs:

1. Pass shell option through runCommand

  const result = spawnSync(command, args, {
    cwd: options.cwd,
    env: options.env,
    encoding: "utf8",
    input: options.input,
-   stdio: options.stdio ?? "pipe"
+   stdio: options.stdio ?? "pipe",
+   shell: options.shell ?? false
  });

2. Enable shell: true on Windows in binaryAvailable

  export function binaryAvailable(command, versionArgs = ["--version"], options = {}) {
+   const platformOptions = process.platform === "win32" ? { ...options, shell: true } : options;
-   const result = runCommand(command, versionArgs, options);
+   const result = runCommand(command, versionArgs, platformOptions);

This is a minimal, targeted fix that only affects binary-availability checks on Windows and does not change behavior on macOS/Linux.

Impact

This bug affects all Windows users who use the Codex plugin through Claude Code CLI (which spawns Git Bash internally). /codex:setup, /codex:review, /codex:rescue, and any other command that calls getCodexAvailability() will fail.

Related

• [BUG] Windows: spawnSync bash ENOENT error after recent update - regression from working state anthropics/claude-code#7470 — Same spawnSync + .cmd ENOENT pattern on Windows