codex: fix multi-agent version CI failures

codex-rs/core/src/session/turn_context.rs

@@ -248,6 +248,7 @@ impl TurnContext {
             compact_prompt: self.compact_prompt.clone(),
             user_instructions: self.user_instructions.clone(),
             collaboration_mode,
+            multi_agent_version: self.multi_agent_version,
             personality: self.personality,
             approval_policy: self.approval_policy.clone(),
             permission_profile: self.permission_profile.clone(),

codex-rs/protocol/src/protocol.rs

@@ -2459,7 +2459,9 @@ impl InitialHistory {
             InitialHistory::Resumed(resumed) => {
                 multi_agent_version_from_items(&resumed.history, Some(resumed.conversation_id))
             }
-            InitialHistory::Forked(items) => multi_agent_version_from_items(items, None),
+            InitialHistory::Forked(items) => {
+                multi_agent_version_from_items(items, /*thread_id*/ None)
+            }
         }
     }
 

codex-rs/thread-store/src/local/mod.rs

@@ -21,6 +21,7 @@ use std::collections::hash_map::Entry;
 use std::path::PathBuf;
 use std::sync::Arc;
 use tokio::sync::Mutex;
+use tokio::sync::Semaphore;
 
 use crate::AppendThreadItemsParams;
 use crate::ArchiveThreadParams;
@@ -59,7 +60,7 @@ use codex_protocol::protocol::MultiAgentVersion;
 pub struct LocalThreadStore {
     pub(super) config: LocalThreadStoreConfig,
     live_recorders: Arc<Mutex<HashMap<ThreadId, RolloutRecorder>>>,
-    multi_agent_version_seed_lock: Arc<Mutex<()>>,
+    multi_agent_version_seed_lock: Arc<Semaphore>,
     state_db: Option<StateDbHandle>,
 }
 
@@ -99,7 +100,7 @@ impl LocalThreadStore {
         Self {
             config,
             live_recorders: Arc::new(Mutex::new(HashMap::new())),
-            multi_agent_version_seed_lock: Arc::new(Mutex::new(())),
+            multi_agent_version_seed_lock: Arc::new(Semaphore::new(/*permits*/ 1)),
             state_db,
         }
     }

codex-rs/thread-store/src/local/set_multi_agent_version.rs

@@ -16,7 +16,13 @@ pub(super) async fn set_multi_agent_version_if_unset(
     store: &LocalThreadStore,
     params: SetMultiAgentVersionIfUnsetParams,
 ) -> ThreadStoreResult<MultiAgentVersion> {
-    let _guard = store.multi_agent_version_seed_lock.lock().await;
+    let _permit = store
+        .multi_agent_version_seed_lock
+        .acquire()
+        .await
+        .map_err(|err| ThreadStoreError::Internal {
+            message: format!("failed to lock thread multi-agent version seed: {err}"),
+        })?;
     let has_live_writer = live_writer::rollout_path(store, params.thread_id)
         .await
         .is_ok();