test for compile failure: lru can not be used with specify

salsa-2022-tests/Cargo.toml

@@ -11,3 +11,4 @@ expect-test = "1.4.0"
 parking_lot = "0.12.1"
 test-log = "0.2.11"
 env_logger = "*"
+trybuild = "1.0"

salsa-2022-tests/tests/compile-fail/lru_can_not_be_used_with_specify.rs

@@ -0,0 +1,16 @@
+#[salsa::jar(db = Db)]
+struct Jar(MyInput, lru_can_not_be_used_with_specify);
+
+trait Db: salsa::DbWithJar<Jar> {}
+
+#[salsa::input(jar = Jar)]
+struct MyInput {
+    field: u32,
+}
+
+#[salsa::tracked(jar = Jar, lru = 3, specify)]
+fn lru_can_not_be_used_with_specify(db: &dyn Db, input: MyInput) -> u32 {
+    input.field(db)
+}
+
+fn main() {}

salsa-2022-tests/tests/compile-fail/lru_can_not_be_used_with_specify.stderr

@@ -0,0 +1,11 @@
+error: `specify` and `lru` cannot be used together
+  --> tests/compile-fail/lru_can_not_be_used_with_specify.rs:11:38
+   |
+11 | #[salsa::tracked(jar = Jar, lru = 3, specify)]
+   |                                      ^^^^^^^
+
+error[E0412]: cannot find type `lru_can_not_be_used_with_specify` in this scope
+ --> tests/compile-fail/lru_can_not_be_used_with_specify.rs:2:21
+  |
+2 | struct Jar(MyInput, lru_can_not_be_used_with_specify);
+  |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not found in this scope

salsa-2022-tests/tests/compile_fail.rs

@@ -0,0 +1,5 @@
+#[test]
+fn compile_fail() {
+    let t = trybuild::TestCases::new();
+    t.compile_fail("tests/compile-fail/*.rs");
+}