diff --git a/src/bootstrap/bin/rustc.rs b/src/bootstrap/bin/rustc.rs
index 6b1be0ca09d0d..0ab5e9c63c94f 100644
--- a/src/bootstrap/bin/rustc.rs
+++ b/src/bootstrap/bin/rustc.rs
@@ -138,21 +138,28 @@ fn main() {
         cmd.arg("-Z").arg("force-unstable-if-unmarked");
     }
 
+    let is_test = args.iter().any(|a| a == "--test");
     if verbose > 1 {
         let rust_env_vars =
             env::vars().filter(|(k, _)| k.starts_with("RUST") || k.starts_with("CARGO"));
+        let prefix = if is_test { "[RUSTC-SHIM] rustc --test" } else { "[RUSTC-SHIM] rustc" };
+        let prefix = match crate_name {
+            Some(crate_name) => format!("{} {}", prefix, crate_name),
+            None => prefix.to_string(),
+        };
         for (i, (k, v)) in rust_env_vars.enumerate() {
-            eprintln!("rustc env[{}]: {:?}={:?}", i, k, v);
+            eprintln!("{} env[{}]: {:?}={:?}", prefix, i, k, v);
         }
-        eprintln!("rustc working directory: {}", env::current_dir().unwrap().display());
+        eprintln!("{} working directory: {}", prefix, env::current_dir().unwrap().display());
         eprintln!(
-            "rustc command: {:?}={:?} {:?}",
+            "{} command: {:?}={:?} {:?}",
+            prefix,
             bootstrap::util::dylib_path_var(),
             env::join_paths(&dylib_path).unwrap(),
             cmd,
         );
-        eprintln!("sysroot: {:?}", sysroot);
-        eprintln!("libdir: {:?}", libdir);
+        eprintln!("{} sysroot: {:?}", prefix, sysroot);
+        eprintln!("{} libdir: {:?}", prefix, libdir);
     }
 
     let start = Instant::now();
@@ -166,7 +173,6 @@ fn main() {
     {
         if let Some(crate_name) = crate_name {
             let dur = start.elapsed();
-            let is_test = args.iter().any(|a| a == "--test");
             // If the user requested resource usage data, then
             // include that in addition to the timing output.
             let rusage_data =