Make the runner mode argument mandatory and enable perf by default

AGENTS.md

@@ -0,0 +1,93 @@
+# AGENTS.md
+
+This file provides guidance to AI coding agents when working with code in this repository.
+
+## Overview
+
+CodSpeed Runner is a Rust CLI application for gathering performance data and uploading reports to CodSpeed. The binary is named `codspeed` and supports local and CI environments including GitHub Actions, GitLab CI, and Buildkite.
+
+## Common Development Commands
+
+### Building and Testing
+```bash
+# Build the project
+cargo build
+
+# Build in release mode
+cargo build --release
+
+# Run tests
+cargo test
+
+# Run specific test
+cargo test <test_name>
+
+# Run tests with output
+cargo test -- --nocapture
+```
+
+### Running the Application
+```bash
+# Build and run
+cargo run -- <subcommand> <args>
+
+# Examples:
+cargo run -- auth login
+cargo run -- run "cargo bench"
+cargo run -- setup
+```
+
+### Code Quality
+```bash
+# Check code without building
+cargo check
+
+# Format code
+cargo fmt
+
+# Run linter
+cargo clippy
+```
+
+## Architecture
+
+The application follows a modular structure:
+
+### Core Modules
+- **`main.rs`**: Entry point with error handling and logging setup
+- **`app.rs`**: CLI definition using clap with subcommands (Run, Auth, Setup)
+- **`api_client.rs`**: CodSpeed GraphQL API client
+- **`auth.rs`**: Authentication management
+- **`config.rs`**: Configuration loading and management
+
+### Run Module (`src/run/`)
+The core functionality for running benchmarks:
+- **`run_environment/`**: CI provider implementations (GitHub Actions, GitLab CI, Buildkite, local)
+- **`runner/`**: Execution modes:
+  - **`valgrind/`**: Instrumentation mode using custom Valgrind
+  - **`wall_time/perf/`**: Walltime mode with perf integration
+- **`uploader/`**: Results upload to CodSpeed
+
+### Key Dependencies
+- `clap`: CLI framework with derive macros
+- `tokio`: Async runtime (current_thread flavor)
+- `reqwest`: HTTP client with middleware/retry
+- `serde`/`serde_json`: Serialization
+- `gql_client`: Custom GraphQL client
+- Platform-specific: `procfs` (Linux), `linux-perf-data`
+
+## Environment Variables
+
+- `CODSPEED_LOG`: Set logging level (debug, info, warn, error)
+- `CODSPEED_API_URL`: Override API endpoint (default: https://gql.codspeed.io/)
+- `CODSPEED_OAUTH_TOKEN`: Authentication token
+
+## Testing
+
+The project uses:
+- Standard Rust `cargo test`
+- `insta` for snapshot testing
+- `rstest` for parameterized tests
+- `temp-env` for environment variable testing
+
+Test files include snapshots in `snapshots/` directories for various run environment providers.

src/run/mod.rs

@@ -50,9 +50,9 @@ pub enum UnwindingMode {
 
 #[derive(Args, Debug, Clone)]
 pub struct PerfRunArgs {
-    /// Enable the performance runner, which uses `perf` to collect performance data.
+    /// Enable the linux perf profiler to collect granular performance data.
     /// This is only supported on Linux.
-    #[arg(long, env = "CODSPEED_PERF_ENABLED", default_value_t = false)]
+    #[arg(long, env = "CODSPEED_PERF_ENABLED", default_value_t = true)]
     enable_perf: bool,
 
     /// The unwinding mode that should be used with perf to collect the call stack.
@@ -88,7 +88,7 @@ pub struct RunArgs {
     pub working_directory: Option<String>,
 
     /// The mode to run the benchmarks in.
-    #[arg(long, default_value_t, value_enum, env = "CODSPEED_RUNNER_MODE")]
+    #[arg(long, value_enum, env = "CODSPEED_RUNNER_MODE")]
     pub mode: RunnerMode,
 
     /// Comma-separated list of instruments to enable. Possible values: mongodb.
@@ -133,10 +133,9 @@ pub struct RunArgs {
     pub command: Vec<String>,
 }
 
-#[derive(ValueEnum, Clone, Default, Debug, Serialize)]
+#[derive(ValueEnum, Clone, Debug, Serialize)]
 #[serde(rename_all = "lowercase")]
 pub enum RunnerMode {
-    #[default]
     Instrumentation,
     Walltime,
 }

src/run/runner/wall_time/perf/mod.rs

@@ -206,7 +206,13 @@ impl PerfRunner {
         harvest_perf_maps_for_pids(profile_folder, &perf_map_pids).await?;
 
         // Append perf maps, unwind info and other metadata
-        bench_data.save_to(profile_folder).unwrap();
+        if let Err(BenchmarkDataSaveError::MissingIntegration) = bench_data.save_to(profile_folder)
+        {
+            warn!(
+                "Perf is enabled, but failed to detect benchmarks. If you wish to disable this warning, set CODSPEED_PERF_ENABLED=false"
+            );
+            return Ok(());
+        }
 
         let elapsed = start.elapsed();
         debug!("Perf teardown took: {elapsed:?}");
@@ -371,8 +377,16 @@ pub struct BenchmarkData {
     unwind_data_by_pid: HashMap<u32, Vec<UnwindData>>,
 }
 
+#[derive(Debug)]
+pub enum BenchmarkDataSaveError {
+    MissingIntegration,
+}
+
 impl BenchmarkData {
-    pub fn save_to<P: AsRef<std::path::Path>>(&self, path: P) -> anyhow::Result<()> {
+    pub fn save_to<P: AsRef<std::path::Path>>(
+        &self,
+        path: P,
+    ) -> Result<(), BenchmarkDataSaveError> {
         for proc_sym in self.symbols_by_pid.values() {
             proc_sym.save_to(&path).unwrap();
         }
@@ -387,7 +401,7 @@ impl BenchmarkData {
             integration: self
                 .integration
                 .clone()
-                .context("Couldn't find integration metadata")?,
+                .ok_or(BenchmarkDataSaveError::MissingIntegration)?,
             bench_order_by_pid: self.bench_order_by_pid.clone(),
             ignored_modules: {
                 let mut to_ignore = vec![];