allow mach-lookup for com.apple.system.opendirectoryd.libinfo (#3334)

in the base sandbox policy. this is [allowed in Chrome
renderers](https://source.chromium.org/chromium/chromium/src/+/main:sandbox/policy/mac/common.sb;l=266;drc=7afa0043cfcddb3ef9dafe5acbfc01c2f7e7df01),
so I feel it's fairly safe.

codex-rs/core/src/seatbelt_base_policy.sbpl

@@ -69,3 +69,8 @@
 ; Added on top of Chrome profile
 ; Needed for python multiprocessing on MacOS for the SemLock
 (allow ipc-posix-sem)
+
+; needed to look up user info, see https://crbug.com/792228
+(allow mach-lookup
+  (global-name "com.apple.system.opendirectoryd.libinfo")
+)

codex-rs/core/tests/suite/seatbelt.rs

@@ -159,6 +159,41 @@ async fn read_only_forbids_all_writes() {
         .await;
 }
 
+/// Verify that user lookups via `pwd.getpwuid(os.getuid())` work under the
+/// seatbelt sandbox. Prior to allowing the necessary mach‑lookup for
+/// OpenDirectory libinfo, this would fail with `KeyError: getpwuid(): uid not found`.
+#[tokio::test]
+async fn python_getpwuid_works_under_seatbelt() {
+    if std::env::var(CODEX_SANDBOX_ENV_VAR) == Ok("seatbelt".to_string()) {
+        eprintln!("{CODEX_SANDBOX_ENV_VAR} is set to 'seatbelt', skipping test.");
+        return;
+    }
+
+    // ReadOnly is sufficient here since we are only exercising user lookup.
+    let policy = SandboxPolicy::ReadOnly;
+
+    let mut child = spawn_command_under_seatbelt(
+        vec![
+            "python3".to_string(),
+            "-c".to_string(),
+            // Print the passwd struct; success implies lookup worked.
+            "import pwd, os; print(pwd.getpwuid(os.getuid()))".to_string(),
+        ],
+        &policy,
+        std::env::current_dir().expect("should be able to get current dir"),
+        StdioPolicy::RedirectForShellTool,
+        HashMap::new(),
+    )
+    .await
+    .expect("should be able to spawn python under seatbelt");
+
+    let status = child
+        .wait()
+        .await
+        .expect("should be able to wait for child process");
+    assert!(status.success(), "python exited with {status:?}");
+}
+
 #[expect(clippy::expect_used)]
 fn create_test_scenario(tmp: &TempDir) -> TestScenario {
     let repo_parent = tmp.path().to_path_buf();