diff --git a/build.sh b/build.sh
index 09389c6530f..a4a37c54373 100755
--- a/build.sh
+++ b/build.sh
@@ -17,7 +17,7 @@ RUSTC="rustc -Zcodegen-backend=$(pwd)/../target/debug/librustc_codegen_cranelift
 $RUSTC mini_core.rs --crate-name mini_core &&
 $RUSTC example.rs &&
 $RUSTC mini_core_hello_world.rs &&
-$RUSTC ../target/libcore/src/libcore/lib.rs 2>&1 | (head -n 10; echo "===="; tail -n 1000) ||
-(rm *.rlib; exit 1)
 
-rm *.rlib
+$RUSTC ../target/libcore/src/libcore/lib.rs 2>&1 | (head -n 10; echo "===="; tail -n 1000)
+cat ../target/log.txt | sort | uniq -c | grep -v "rval unsize move" | grep -v "rval len"
+rm *.rlib ../target/log.txt
diff --git a/src/lib.rs b/src/lib.rs
index b55497394a6..f09f62ca048 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -242,12 +242,15 @@ impl CodegenBackend for CraneliftCodegenBackend {
         let mut context = Context::new();
 
         {
+            use std::io::Write;
             let mut cx = CodegenCx {
                 tcx,
                 module: &mut module,
                 constants: HashMap::new(),
             };
 
+            let mut log = ::std::fs::File::create("../target/log.txt").unwrap();
+
             for mono_item in
                 collector::collect_crate_mono_items(tcx, collector::MonoItemCollectionMode::Eager).0
             {
@@ -258,7 +261,10 @@ impl CodegenBackend for CraneliftCodegenBackend {
                 }));
                 if let Err(err) = res {
                     match err.downcast::<NonFatal>() {
-                        Ok(non_fatal) => tcx.sess.err(&non_fatal.0),
+                        Ok(non_fatal) => {
+                            writeln!(log, "{}", &non_fatal.0);
+                            tcx.sess.err(&non_fatal.0)
+                        }
                         Err(err) => ::std::panic::resume_unwind(err),
                     }
                 }