Fix tests

Move 512-bit distribution quality check to slow-tests
Better assertion-failure text

src/hazmat/uniform_sieve.rs

@@ -339,31 +339,31 @@ mod tests {
     fn uniform_sieve_primes() {
         let p: U64 = U64::generate_prime();
         info!("64 bit prime={p:?}");
-        assert!(is_prime(&p));
+        assert!(is_prime_with_rng(&mut OsRng, &p));
 
         let p = U128::generate_prime();
         info!("128 bit prime={p:?}");
-        assert!(is_prime(&p));
+        assert!(is_prime_with_rng(&mut OsRng, &p));
 
         let p = U256::generate_prime();
         info!("256 bit prime={p:?}");
-        assert!(is_prime(&p));
+        assert!(is_prime_with_rng(&mut OsRng, &p));
 
         let p = U512::generate_prime();
         info!("512 bit prime={p:?}");
-        assert!(is_prime(&p));
+        assert!(is_prime_with_rng(&mut OsRng, &p));
 
         let p = U1024::generate_prime();
         info!("1024 bit prime={p:?}");
-        assert!(is_prime(&p));
+        assert!(is_prime_with_rng(&mut OsRng, &p));
 
         let p = U2048::generate_prime();
         info!("2048 bit prime={p:?}");
-        assert!(is_prime(&p));
+        assert!(is_prime_with_rng(&mut OsRng, &p));
         // // This is very slow
         // let p = U4096::generate_prime();
         // info!("4096 bit prime={p:?}");
-        // assert!(is_prime(&p));
+        // assert!(is_prime_with_rng(&mut OsRng, &p));
     }
 
     #[test_log::test]
@@ -378,6 +378,7 @@ mod tests {
     fn check_distribution_quality_u256() {
         check_distribution_quality::<U256>();
     }
+    #[cfg(feature = "tests-exhaustive")]
     #[test_log::test]
     fn check_distribution_quality_u512() {
         check_distribution_quality::<U512>();

src/stat_utils.rs

@@ -25,7 +25,7 @@ where
         "Sampled {sample_count} {} bit primes. p={p_value}, chi_squared={chi_square_stat}",
         T::BITS
     );
-    assert!(p_value > 0.05);
+    assert!(p_value > 0.05, "Expected a p_value larger than 0.05, instead found {p_value}, failing to prove that the distribution is uniform.");
     assert!(chi_square_stat < 16.92, "For p 0.05, the critical chi-square value is 16.92, instead we got {chi_square_stat}, failing the hypothesis that the distribution is uniform.");
 }