feat(log): add bounded diagnostic transport

libs/kaptan-mavlink/build.rs

@@ -3,17 +3,23 @@ use std::path::PathBuf;
 fn main() {
     let manifest_directory = PathBuf::from(std::env::var("CARGO_MANIFEST_DIR").unwrap());
     let dialect = manifest_directory.join("definitions/kaptan.xml");
-    let output_directory = std::env::var("OUT_DIR").unwrap();
-    let dialect_source = std::fs::read_to_string(&dialect).unwrap();
-    let generated = mavlink_bindgen::generate(
-        mavlink_bindgen::XmlDefinitions::Files(vec![dialect]),
-        output_directory,
-    )
-    .unwrap();
-
-    mavlink_bindgen::emit_cargo_build_messages(&generated);
+    let log = manifest_directory.join("definitions/kaptan/log.xml");
+    for definition in [&dialect, &log] {
+        println!("cargo::rerun-if-changed={}", definition.display());
+    }
     println!("cargo::rustc-check-cfg=cfg(kaptan_has_messages)");
-    if dialect_source.contains("<message ") {
+    // The upstream generator conditionally emits derives for these optional
+    // ecosystem crates. Kaptan deliberately does not expose those incomplete
+    // features, so tell rustc the generated inactive cfgs are intentional.
+    println!("cargo::rustc-check-cfg=cfg(feature, values(\"serde\", \"arbitrary\", \"ts-rs\"))");
+    if std::env::var_os("CARGO_FEATURE_DIALECT_KAPTAN").is_some() {
+        let output_directory = std::env::var("OUT_DIR").unwrap();
+        let generated = mavlink_bindgen::generate(
+            mavlink_bindgen::XmlDefinitions::Files(vec![dialect]),
+            output_directory,
+        )
+        .unwrap();
+        mavlink_bindgen::emit_cargo_build_messages(&generated);
         println!("cargo::rustc-cfg=kaptan_has_messages");
     }
 }