Merge pull request #6420 from obycode/test/boot_to_epoch_3_flakiness

test: fix flakiness from `boot_to_epoch_3`

Author: obycode

stacks-node/src/tests/signer/v0.rs

@@ -143,20 +143,36 @@ impl<Z: SpawnedSignerTrait> SignerTest<Z> {
             &self.running_nodes.btc_regtest_controller,
             Some(self.num_stacking_cycles),
         );
+
         info!("Waiting for signer set calculation.");
         // Make sure the signer set is calculated before continuing or signers may not
         // recognize that they are registered signers in the subsequent burn block event
         let reward_cycle = self.get_current_reward_cycle() + 1;
+        let mut last_probe = Instant::now();
         wait_for(120, || {
-            let Ok(Some(reward_set)) = self.stacks_client.get_reward_set_signers(reward_cycle)
-            else {
-                return Ok(false);
-            };
-
-            debug!("Signer set: {reward_set:?}");
-            Ok(true)
+            match self.stacks_client.get_reward_set_signers(reward_cycle).unwrap_or_default() {
+                Some(reward_set) => {
+                    debug!("Signer set: {reward_set:?}");
+                    Ok(true)
+                }
+                None => {
+                    // If we've been waiting ~30s since the last probe, maybe the last block failed
+                    // so we should try to mine another block
+                    if last_probe.elapsed() >= Duration::from_secs(30) {
+                        warn!(
+                            "Timed out waiting for reward set calculation. Mining another block to try again."
+                        );
+                        self.running_nodes
+                            .btc_regtest_controller
+                            .build_next_block(1);
+                        last_probe = Instant::now();
+                    }
+                    Ok(false)
+                }
+            }
         })
         .expect("Timed out waiting for reward set calculation");
+
         info!("Signer set calculated");
 
         // Manually consume one more block to ensure signers refresh their state