fix(valgrind): install libc6-dbg during valgrind setup

GitHub runners do not ship libc debug symbols by default, which leads
to unresolved symbols in exec CLI simulation benchmarks. Install
libc6-dbg via apt on supported systems after installing valgrind.

Fixes COD-2770

Author: not-matthias

src/executor/helpers/apt.rs

@@ -87,6 +87,14 @@ where
     Ok(())
 }
 
+/// Returns whether a package is currently installed according to `dpkg`.
+pub fn is_package_installed(package: &str) -> bool {
+    Command::new("dpkg")
+        .args(["-s", package])
+        .output()
+        .is_ok_and(|output| output.status.success())
+}
+
 pub fn install(system_info: &SystemInfo, packages: &[&str]) -> Result<()> {
     if !is_system_compatible(system_info) {
         bail!(

src/executor/valgrind/setup.rs

@@ -177,7 +177,7 @@ fn is_valgrind_installed() -> bool {
     matches!(
         get_valgrind_status().status,
         ToolInstallStatus::Installed { .. }
-    )
+    ) && apt::is_package_installed("libc6-dbg")
 }
 
 pub async fn install_valgrind(
@@ -193,10 +193,14 @@ pub async fn install_valgrind(
             let binary = get_codspeed_valgrind_binary(system_info)?;
             let deb_path = env::temp_dir().join("valgrind-codspeed.deb");
             download_pinned_file(binary, &deb_path).await?;
-            apt::install(system_info, &[deb_path.to_str().unwrap()])?;
+
+            // Install libc debug symbols alongside valgrind, as GitHub runners
+            // do not include them by default. Keeping them in the same install
+            // call puts them under the same caching and idempotency logic.
+            apt::install(system_info, &[deb_path.to_str().unwrap(), "libc6-dbg"])?;
 
             // Return package names for caching
-            Ok(vec!["valgrind".to_string()])
+            Ok(vec!["valgrind".to_string(), "libc6-dbg".to_string()])
         },
     )
     .await