1 files changed, 7 insertions, 0 deletions
diff --git a/third_party/rust/hawk/build.rs b/third_party/rust/hawk/build.rs
new file mode 100644
index 0000000000..a5e367f69b
--- /dev/null
+++ b/third_party/rust/hawk/build.rs
@@ -0,0 +1,7 @@
+// Just check that we aren't asked to use an impossible configuration.
+fn main() {
+    assert!(
+        !(cfg!(feature = "use_ring") && cfg!(feature = "use_openssl")),
+        "Cannot configure `hawk` with both `use_ring` and `use_openssl`!"
+    );
+}