feat(cli): add tracing-samply to profiling (#20546)

bin/reth-bench-compare/src/cli.rs

@@ -329,6 +329,7 @@ pub(crate) async fn run_comparison(args: Args, _ctx: CliContext) -> Result<()> {
         output_dir.clone(),
         git_manager.clone(),
         args.features.clone(),
+        args.profile,
     )?;
     // Initialize node manager
     let mut node_manager = NodeManager::new(&args);

bin/reth-bench-compare/src/compilation.rs

@@ -14,6 +14,7 @@ pub(crate) struct CompilationManager {
     output_dir: PathBuf,
     git_manager: GitManager,
     features: String,
+    enable_profiling: bool,
 }
 
 impl CompilationManager {
@@ -23,8 +24,9 @@ impl CompilationManager {
         output_dir: PathBuf,
         git_manager: GitManager,
         features: String,
+        enable_profiling: bool,
     ) -> Result<Self> {
-        Ok(Self { repo_root, output_dir, git_manager, features })
+        Ok(Self { repo_root, output_dir, git_manager, features, enable_profiling })
     }
 
     /// Detect if the RPC endpoint is an Optimism chain
@@ -100,9 +102,18 @@ impl CompilationManager {
         let mut cmd = Command::new("cargo");
         cmd.arg("build").arg("--profile").arg("profiling");
 
-        // Add features
-        cmd.arg("--features").arg(&self.features);
-        info!("Using features: {}", self.features);
+        // Append samply feature when profiling to enable tracing span markers.
+        // NOTE: The `samply` feature must exist in the branch being compiled. If comparing
+        // against an older branch that predates the samply integration, compilation will fail
+        // or markers won't appear. In that case, omit --profile or ensure both branches
+        // include the samply feature support.
+        let features = if self.enable_profiling && !self.features.contains("samply") {
+            format!("{},samply", self.features)
+        } else {
+            self.features.clone()
+        };
+        cmd.arg("--features").arg(&features);
+        info!("Using features: {}", features);
 
         // Add bin-specific arguments for optimism
         if is_optimism {

bin/reth/Cargo.toml

@@ -87,6 +87,10 @@ otlp = [
     "reth-ethereum-cli/otlp",
     "reth-node-core/otlp",
 ]
+samply = [
+    "reth-ethereum-cli/samply",
+    "reth-node-core/samply",
+]
 js-tracer = [
     "reth-node-builder/js-tracer",
     "reth-node-ethereum/js-tracer",