The following test script fails in the codex sandbox:
```
import multiprocessing
from multiprocessing import Lock, Process
def f(lock):
with lock:
print("Lock acquired in child process")
if __name__ == '__main__':
lock = Lock()
p = Process(target=f, args=(lock,))
p.start()
p.join()
```
with
```
Traceback (most recent call last):
File "/Users/david.hao/code/codex/codex-rs/cli/test.py", line 9, in <module>
lock = Lock()
^^^^^^
File "/Users/david.hao/.local/share/uv/python/cpython-3.12.9-macos-aarch64-none/lib/python3.12/multiprocessing/context.py", line 68, in Lock
return Lock(ctx=self.get_context())
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/david.hao/.local/share/uv/python/cpython-3.12.9-macos-aarch64-none/lib/python3.12/multiprocessing/synchronize.py", line 169, in __init__
SemLock.__init__(self, SEMAPHORE, 1, 1, ctx=ctx)
File "/Users/david.hao/.local/share/uv/python/cpython-3.12.9-macos-aarch64-none/lib/python3.12/multiprocessing/synchronize.py", line 57, in __init__
sl = self._semlock = _multiprocessing.SemLock(
^^^^^^^^^^^^^^^^^^^^^^^^^
PermissionError: [Errno 1] Operation not permitted
```
After reading, adding this line to the sandbox configs fixes things -
MacOS multiprocessing appears to use sem_lock(), which opens an IPC
which is considered a disk write even though no file is created. I
interrogated ChatGPT about whether it's okay to loosen, and my
impression after reading is that it is, although would appreciate a
close look
Breadcrumb: You can run `cargo run -- debug seatbelt --full-auto <cmd>`
to test the sandbox
codex-core
This crate implements the business logic for Codex. It is designed to be used by the various Codex UIs written in Rust.
Dependencies
Note that codex-core makes some assumptions about certain helper utilities being available in the environment. Currently, this
macOS
Expects /usr/bin/sandbox-exec to be present.
Linux
Expects the binary containing codex-core to run the equivalent of codex debug landlock when arg0 is codex-linux-sandbox. See the codex-arg0 crate for details.
All Platforms
Expects the binary containing codex-core to simulate the virtual apply_patch CLI when arg1 is --codex-run-as-apply-patch. See the codex-arg0 crate for details.