Fail test compilation if compare feature is missing
//! Unit tests
-#[cfg(not(feature = "proptest-support"))]
-compile_error!("Tests must be run with feature proptest-support");
+#[cfg(any(not(feature = "proptest-support"), not(feature = "compare")))]
+compile_error!("Tests must be run with features `proptest-support` and `compare`");
mod unit_tests;
