docs: add debugging

librustzcash-wrapper/src/lib.rs

@@ -2418,6 +2418,7 @@ pub extern "C" fn rust_wrapper_create_transaction(
             Err(e) => {
                 match e {
                     Error::InsufficientFunds(y) => {
+                        println!("ins funds: {:?}", y);
                         let x = Hhex {bytes: vec![0]};
                         marshall_to_haskell_var(&x, out, out_len, RW);
                     },