diff --git a/src/tools/compiletest/src/common.rs b/src/tools/compiletest/src/common.rs
index 703b87634cec..878e87e406db 100644
--- a/src/tools/compiletest/src/common.rs
+++ b/src/tools/compiletest/src/common.rs
@@ -169,7 +169,7 @@ impl fmt::Display for Debugger {
 }
 
 /// Configuration for compiletest
-#[derive(Clone)]
+#[derive(Debug, Clone)]
 pub struct Config {
     /// `true` to to overwrite stderr/stdout files instead of complaining about changes in output.
     pub bless: bool,
diff --git a/src/tools/compiletest/src/runtest.rs b/src/tools/compiletest/src/runtest.rs
index dd0c68ecd496..4ecd487a71d5 100644
--- a/src/tools/compiletest/src/runtest.rs
+++ b/src/tools/compiletest/src/runtest.rs
@@ -1877,7 +1877,8 @@ impl<'test> TestCx<'test> {
         emit_metadata: EmitMetadata,
         allow_unused: AllowUnused,
     ) -> Command {
-        let is_rustdoc = self.is_rustdoc();
+        let is_aux = input_file.components().map(|c| c.as_os_str()).any(|c| c == "auxiliary");
+        let is_rustdoc = self.is_rustdoc() && !is_aux;
         let mut rustc = if !is_rustdoc {
             Command::new(&self.config.rustc_path)
         } else {
@@ -3502,6 +3503,7 @@ impl ProcRes {
     }
 }
 
+#[derive(Debug)]
 enum TargetLocation {
     ThisFile(PathBuf),
     ThisDirectory(PathBuf),