also test getrandom directly

Author: RalfJung

test-cargo-miri/Cargo.lock

@@ -16,6 +16,7 @@ issue_1705 = { path = "issue-1705" }
 
 [dev-dependencies]
 rand = { version = "0.7", features = ["small_rng"] }
+getrandom = { version = "0.2" }
 serde_derive = "1.0" # not actually used, but exercises some unique code path (`--extern` .so file)
 
 [lib]

test-cargo-miri/Cargo.toml

@@ -24,6 +24,10 @@ fn does_not_work_on_miri() {
 
 #[test]
 fn entropy_rng() {
+    // Test `getrandom` directly.
+    let mut data = vec![0; 16];
+    getrandom::getrandom(&mut data).unwrap();
+
     // Try seeding with "real" entropy.
     let mut rng = SmallRng::from_entropy();
     let _val = rng.gen::<i32>();