Fix intermittent errors in the groth16 verifier tests (#2412)

zebra-consensus/src/primitives/groth16/tests.rs

@@ -61,9 +61,31 @@ where
 
 #[tokio::test]
 async fn verify_sapling_groth16() {
-    // Since we expect these to pass, we can use the communal verifiers.
+    // Use separate verifiers so shared batch tasks aren't killed when the test ends (#2390)
-    let mut spend_verifier = groth16::SPEND_VERIFIER.clone();
+    let mut spend_verifier = Fallback::new(
-    let mut output_verifier = groth16::OUTPUT_VERIFIER.clone();
+        Batch::new(
+            Verifier::new(&PARAMS.sapling.spend.vk),
+            crate::primitives::MAX_BATCH_SIZE,
+            crate::primitives::MAX_BATCH_LATENCY,
+        ),
+        tower::service_fn(
+            (|item: Item| {
+                ready(item.verify_single(&prepare_verifying_key(&PARAMS.sapling.spend.vk)))
+            }) as fn(_) -> _,
+        ),
+    );
+    let mut output_verifier = Fallback::new(
+        Batch::new(
+            Verifier::new(&PARAMS.sapling.output.vk),
+            crate::primitives::MAX_BATCH_SIZE,
+            crate::primitives::MAX_BATCH_LATENCY,
+        ),
+        tower::service_fn(
+            (|item: Item| {
+                ready(item.verify_single(&prepare_verifying_key(&PARAMS.sapling.output.vk)))
+            }) as fn(_) -> _,
+        ),
+    );
 
     let transactions = zebra_test::vectors::MAINNET_BLOCKS
         .clone()
@@ -125,10 +147,9 @@ where
 }
 
 #[tokio::test]
-#[should_panic]
 async fn correctly_err_on_invalid_output_proof() {
-    // Since we expect these to fail, we don't want to poison the communal
+    // Use separate verifiers so shared batch tasks aren't killed when the test ends (#2390).
-    // verifiers.
+    // Also, since we expect these to fail, we don't want to slow down the communal verifiers.
     let mut output_verifier = Fallback::new(
         Batch::new(
             Verifier::new(&PARAMS.sapling.output.vk),
@@ -149,5 +170,5 @@ async fn correctly_err_on_invalid_output_proof() {
 
     verify_invalid_groth16_output_description(&mut output_verifier, block.transactions)
         .await
-        .unwrap()
+        .expect_err("unexpected success checking invalid groth16 inputs");
 }