fix: syncronizer shutdown race condition

core/cli/src/commands/run.rs

@@ -40,7 +40,7 @@ where
 
         tokio::select! {
             _ = &mut shutdown_future => break,
-            checkpoint_hash = checkpoint_fut => {
+            Some(checkpoint_hash) = checkpoint_fut => {
                 // get the checkpoint from the blockstore
                 let checkpoint = node
                     .provider()

core/e2e/tests/syncronizer.rs

@@ -67,7 +67,7 @@ async fn e2e_syncronize_state() -> Result<()> {
     let (pubkey, syncronizer) = swarm.get_non_genesis_committee_syncronizer().pop().unwrap();
 
     // Wait for the syncronizer to detect that we are behind and send the checkpoint hash.
-    let ckpt_hash = syncronizer.next_checkpoint_hash().await;
+    let ckpt_hash = syncronizer.next_checkpoint_hash().await.unwrap();
 
     // Get the hash for this checkpoint from our blockstore. The syncronizer should have downloaded
     // it.

core/interfaces/src/syncronizer.rs

@@ -7,6 +7,7 @@ use crate::collection::Collection;
 pub trait SyncronizerInterface<C: Collection>: BuildGraph + Sized + Send + Sync {
     /// Returns the blake3hash of the next checkpoint to load, after
     /// it has already downloaded by the blockstore server.
+    /// If it returns None it means the Node is not ever going to checkpoint and should be shutting down
     #[pending]
-    async fn next_checkpoint_hash(&self) -> Blake3Hash;
+    async fn next_checkpoint_hash(&self) -> Option<Blake3Hash>;
 }

core/syncronizer/src/syncronizer.rs

@@ -168,11 +168,11 @@ impl<C: Collection> fdi::BuildGraph for Syncronizer<C> {
 impl<C: Collection> SyncronizerInterface<C> for Syncronizer<C> {
     /// Returns a socket that will send accross the blake3hash of the checkpoint
     /// Will send it after it has already downloaded from the blockstore server
-    async fn next_checkpoint_hash(&self) -> Blake3Hash {
+    async fn next_checkpoint_hash(&self) -> Option<Blake3Hash> {
         let State::Running(rx) = &self.state else {
             panic!("syncronizer must be started");
         };
-        rx.recv().await.unwrap()
+        rx.recv().await.ok()
     }
 }