workspace-write sandbox denies file reads outside workspace on macOS, breaking pnpm/Corepack

Summary

Under the default workspace-write sandbox on macOS, read/stat/open on files outside the workspace returns EPERM ("Operation not permitted"), including /System/Library/OpenSSL/openssl.cnf and Homebrew/nvm paths. This is not a write or network restriction; plain reads are blocked. As a result, Node cannot load its OpenSSL config, and pnpm/Corepack cannot run. Running with --sandbox danger-full-access makes everything work, which points to the sandbox profile rather than macOS TCC or the toolchain.

Is denying reads outside the workspace the intended behavior for workspace-write? If so, could Node's OpenSSL config read (and script/symlink-based tools such as pnpm/Corepack) be accommodated? If not, this looks like a regression.

Environment

| | |
|---|---|
| macOS | Tahoe 26.5.1 (build 25F80) |
| Kernel | Darwin 25.5.0 arm64 |
| Codex CLI | 0.141.0 |
| Shell | zsh |
| Node | v24.13.0 (nvm) |
| pnpm | 10.30.2 (Corepack shim) |
| Sandbox | workspace-write (default config, no custom writable_roots) |

Minimal reproduction (no toolchain involved)

In a normal workspace-write session:

ls -ld /System/Library/OpenSSL              # success (dir stat OK)
ls -l  /System/Library/OpenSSL/openssl.cnf  # Operation not permitted
cat    /System/Library/OpenSSL/openssl.cnf  # Operation not permitted
ls -l  /opt/homebrew/bin/brew               # Operation not permitted

stat() on the directory succeeds, but stat()/open() on files within it is denied, so this is a file read/stat denial rather than a missing or untraversable path.

The same commands succeed under codex --sandbox danger-full-access:

ls -l /opt/homebrew/bin/pnpm                 # ../Cellar/pnpm/10.21.0/bin/pnpm
pnpm --version                               # 10.30.2

Impact on the Node toolchain

# Node cannot read its OpenSSL config:
node --input-type=module -e "console.log(process.version)"
# OpenSSL configuration error
# BIO_new_file: Operation not permitted
# calling fopen(/System/Library/OpenSSL//openssl.cnf, rb)

# Workaround (point OPENSSL_CONF at a nonexistent file so Node skips it):
env OPENSSL_CONF=/private/tmp/nonexistent-openssl.cnf \
  node --input-type=module -e "console.log(process.version)"
# v24.13.0 (exit 0)

# pnpm / Corepack cannot run:
pnpm --version       # exit 127, zsh:1: operation not permitted: pnpm
corepack --version   # exit 127, zsh:1: operation not permitted: corepack

which/command -v report these as not found (the sandbox denies stat during PATH lookup), yet zsh still attempts the exec by name and the kernel returns EPERM.

Observed behavior: exec sometimes works, reads/stat do not

Probing each path from Node's fs and fs.accessSync (X_OK/R_OK) inside the workspace-write sandbox:

| path | type | stat | readFile | access X | access R |
|---|---|---|---|---|---|
| ~/.nvm/.../bin/node | Mach-O binary | EPERM | EPERM | OK | EPERM |
| ~/.nvm/.../bin/pnpm | symlink | EPERM | EPERM | EPERM | EPERM |
| .../corepack/dist/pnpm.js | JS shim | EPERM | EPERM | OK | EPERM |
| /opt/homebrew/bin/brew | Mach-O binary | EPERM | EPERM | OK | EPERM |
| /System/Library/OpenSSL/openssl.cnf | config file | EPERM | EPERM | — | EPERM |

From the observed behavior, it looks like file reads/stat calls are denied while some direct exec paths are still allowed. This is consistent with the otherwise confusing results:

• node -v works, while the same node appears "not found" to which/ls/fs.stat.
• process.execPath is reported as node (not an absolute path), consistent with stat on argv0 being denied.
• pnpm/Corepack fail even though some exec checks pass, likely because launching a symlink/JS shim involves resolving or reading files that are denied by the sandbox.

Net effect: a native binary such as node can execute, but tools that need to read files outside the workspace during startup (symlinks, JS shims, shebang scripts, config files, which/stat) fail with EPERM.

Additional notes

• danger-full-access makes all of the above succeed, which makes this look specific to Codex's sandbox profile rather than a general macOS TCC / Full Disk Access issue.
• It reproduces with a plain cat/ls on system files, so it is not a Corepack network/cache issue.
• For reference, another sandboxed coding tool on the same machine, same repo, and same Node/pnpm setup can run pnpm check, pnpm typecheck, and pnpm test without EPERM.

Searched for duplicates

No exact match found (searched workspace-write with EPERM / Operation not permitted and sandbox / danger-full-access).