Codex CLI on Native Windows with PowerShell: Vitest spawn EPERM and frequent fail to apply patch on large edits

What version of Codex CLI is running?

codex-cli 0.118.0

What subscription do you have?

plus

Which model were you using?

gpt-5.4 high fast

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What terminal emulator and version are you using (if applicable)?

Windows Powershell

What issue are you seeing?

I am seeing two recurring issues with Codex CLI on native Windows.

1. Vitest fails to start inside Codex with:

spawn EPERM
This happens while loading vitest.config.mts, before the tests actually run.

Command:
pnpm exec vitest run --config ./vitest.config.mts tests/int/order-draft-pages.int.spec.ts tests/int/account-pages.int.spec.ts

1. Larger edits often fail with:

fail to apply patch

This seems to happen more often when Codex generates a long patch, edits a long file, or makes multiple nearby edits in the same file.

Relevant config:
approval_policy = "never"
sandbox_mode = "workspace-write"

[windows]
sandbox = "elevated"

What steps can reproduce the bug?

Issue 1: spawn EPERM

Steps:

1. Run Codex CLI on native Windows.
2. Use PowerShell as the shell.
3. Use this configuration:

• approval_policy = "never"
• sandbox_mode = "workspace-write"
• [windows] sandbox = "elevated"

1. Ask Codex to run:

pnpm exec vitest run --config ./vitest.config.mts tests/int/order-draft-pages.int.spec.ts

1. Codex fails during startup while loading vitest.config.mts with spawn EPERM.

Important comparison:

• The same command runs successfully in my normal local PowerShell session outside Codex.
• The failure happens when Codex tries to run it.

Issue 2: fail to apply patch

Steps:

1. Use Codex CLI on native Windows with the same configuration.
2. Ask Codex to make a relatively large edit in a long file, or generate a long patch touching multiple nearby sections.
3. Codex frequently returns fail to apply patch instead of completing the edit.

What is the expected behavior?

Expected behavior for Issue 1:

• Codex should be able to run the same pnpm/Vitest command successfully if it works in normal local PowerShell, or
• Codex should return a clearer environment-specific error explaining exactly which Windows sandbox restriction is blocking subprocess creation.

Expected behavior for Issue 2:

• Codex should be able to apply larger patches reliably, even for long files or multi-section edits, or
• Codex should provide a more specific error message describing the actual limitation, such as patch size limit, context mismatch, or Windows-specific patch application failure.

Additional information

Additional context:

• This is on native Windows, not WSL.
• I am using PowerShell.
• The Vitest issue appears before test execution, during toolchain/config startup.
• The patch issue is frequent enough to disrupt normal development in larger files.
• Because the same pnpm command works in my normal local PowerShell session, this looks more like a Codex execution/sandbox issue than a project-level pnpm or Vitest issue.