feat(build): Added tracing spans for rustc invocations

Author: ranger-ross

src/cargo/core/compiler/mod.rs

@@ -402,6 +402,13 @@ fn rustc(
                 let outfile = BufWriter::new(paths::create(&file)?);
                 serde_json::to_writer(outfile, &sbom)?;
             }
+            let span = tracing::span!(
+                tracing::Level::TRACE,
+                "rustc",
+                package = name.as_str(),
+                process = rustc.to_string()
+            )
+            .entered();
 
             let result = exec
                 .exec(
@@ -448,6 +455,8 @@ fn rustc(
                     format!("could not compile {name}{errors}{warnings}")
                 });
 
+            drop(span);
+
             if let Err(e) = result {
                 if let Some(diagnostic) = failed_scrape_diagnostic {
                     state.warning(diagnostic);