docs(macros/generate): Improve error output

src/macros/generate/convert/auxiliary/c/type/mod.rs

@@ -68,7 +68,9 @@ impl Type {
                     .map(|r#type| r#type.to_auxiliary_c(false, field_name))
                     .collect();
 
-                let field_name = field_name.expect("This is some, when I'm a function type").to_rust();
+                let field_name = field_name
+                    .expect("This is some, when it's a function type")
+                    .to_rust();
 
                 quote! {
                     #output (*#field_name) (#(#inputs),*)

src/macros/generate/host/mod.rs

@@ -34,7 +34,9 @@ pub mod rust;
 
 pub fn format_rust(input: TokenStream2) -> String {
     prettyplease::unparse(
-        &syn::parse2(input).expect("This code was generated, it should also be parsable"),
+        &syn::parse2(input.clone()).map_err(|err| {
+            eprintln!("{}:\n===\n{}\n===\n", err, input);
+        }).expect("This code was generated, it should also be parsable"),
     )
 }