message: Make sure build.sh exits with non-zero error code on errors
diff: @@ -7,6 +7,6 @@ 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
  +$RUSTC ../target/libcore/src/libcore/lib.rs &&
  rm *.rlib
  