We don't support WASM in our Rust build yet.

--- a/tests/build.rs
+++ b/tests/build.rs
@@ -3554,6 +3554,7 @@
 }
 
 #[test]
+#[ignore]
 fn wasm32_final_outputs() {
     use cargo::core::{Shell, Target, Workspace};
     use cargo::ops::{self, BuildConfig, Context, CompileMode, CompileOptions, Kind, Unit};