fix(windows-sandbox): decouple runner launch cwd from workspace

codex-rs/windows-sandbox-rs/src/elevated/runner_client.rs

@@ -48,6 +48,12 @@ const RUNNER_SPAWN_READY_POLL_INTERVAL: Duration = Duration::from_millis(50);
 const RUNNER_ERROR_MODE_FLAGS: u32 = 0x0001 | 0x0002;
 const WAIT_OBJECT_0: u32 = 0;
 
+fn runner_launch_cwd(codex_home: &Path) -> std::io::Result<std::path::PathBuf> {
+    let launch_cwd = codex_home.join(".sandbox");
+    std::fs::create_dir_all(&launch_cwd)?;
+    Ok(launch_cwd)
+}
+
 pub(crate) struct RunnerTransport {
     pipe_write: File,
     pipe_read: File,
@@ -241,7 +247,8 @@ pub(crate) fn spawn_runner_transport(
     );
     let mut cmdline_vec = to_wide(&runner_full_cmd);
     let exe_w = to_wide(&runner_cmdline);
-    let cwd_w = to_wide(cwd);
+    let launch_cwd = runner_launch_cwd(codex_home)?;
+    let cwd_w = to_wide(&launch_cwd);
     let user_w = to_wide(&sandbox_creds.username);
     let domain_w = to_wide(".");
     let password_w = to_wide(&sandbox_creds.password);
@@ -392,3 +399,17 @@ fn wait_for_complete_frame(pipe_read: &File, timeout: Duration) -> Result<()> {
         std::thread::sleep(RUNNER_SPAWN_READY_POLL_INTERVAL);
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::runner_launch_cwd;
+
+    #[test]
+    fn runner_launch_cwd_uses_local_sandbox_dir() {
+        let temp = tempfile::tempdir().expect("tempdir");
+        let launch_cwd = runner_launch_cwd(temp.path()).expect("launch cwd");
+
+        assert_eq!(launch_cwd, temp.path().join(".sandbox"));
+        assert!(launch_cwd.is_dir());
+    }
+}

codex-rs/windows-sandbox-rs/src/unified_exec/backends/elevated.rs

@@ -7,6 +7,7 @@ use crate::ipc_framed::EmptyPayload;
 use crate::ipc_framed::FramedMessage;
 use crate::ipc_framed::Message;
 use crate::ipc_framed::SpawnRequest;
+use crate::path_normalization::resolve_sandbox_path;
 use crate::runner_client::spawn_runner_transport;
 use crate::spawn_prep::prepare_elevated_spawn_context;
 use anyhow::Result;
@@ -40,12 +41,14 @@ pub(crate) async fn spawn_windows_sandbox_session_elevated(
         &command,
     )?;
 
+    let resolved_cwd = resolve_sandbox_path(cwd);
+    let resolved_policy_cwd = resolve_sandbox_path(sandbox_policy_cwd);
     let spawn_request = SpawnRequest {
         command: command.clone(),
-        cwd: cwd.to_path_buf(),
+        cwd: resolved_cwd,
         env: env_map.clone(),
         policy_json_or_preset: policy_json_or_preset.to_string(),
-        sandbox_policy_cwd: sandbox_policy_cwd.to_path_buf(),
+        sandbox_policy_cwd: resolved_policy_cwd,
         codex_home: elevated.common.sandbox_base.clone(),
         real_codex_home: codex_home.to_path_buf(),
         cap_sids: elevated.cap_sids.clone(),