rpc/system_metrics.rs: Added rustversion label to garage_build_info metric.

src/util/Cargo.toml

@@ -47,6 +47,9 @@ hyper = "0.14"
 
 opentelemetry = { version = "0.17", features = [ "rt-tokio", "metrics", "trace" ] }
 
+[build-dependencies]
+rustc_version = "0.4.0"
+
 [dev-dependencies]
 mktemp = "0.5"
 

src/util/build.rs

@@ -0,0 +1,8 @@
+use rustc_version::version;
+
+fn main() {
+	// Acquire the version of Rust used to compile, this is added as a label to
+	// the garage_build_info metric.
+	let v = version().unwrap();
+	println!("cargo:rustc-env=RUSTC_VERSION={v}");
+}

src/util/version.rs

@@ -26,3 +26,7 @@ pub fn init_version(version: &'static str) {
 pub fn init_features(features: &'static [&'static str]) {
 	FEATURES.store(Some(Arc::new(features)));
 }
+
+pub fn rust_version() -> &'static str {
+	env!("RUSTC_VERSION")
+}