try

src/engine.rs

@@ -1,4 +1,6 @@
 use crate::config::Engine;
+
+use hidapi::HidApi;
 use rusb::UsbContext;
 
 pub trait InputEngine {
@@ -18,6 +20,20 @@ struct InputEngineDevice {
 }
 
 pub fn build_input_engine_device(cfg: &Engine) -> Result<Box<dyn InputEngine>, String> {
+   let _device_cfg = cfg.device.as_ref().unwrap();
+
+
+   match HidApi::new() {
+      Ok(api) => {
+         for device in api.devices() {
+            println!("{:#?}", device.product_string);
+         }
+      },
+      Err(e) => {
+         eprintln!("Error: {}", e);
+      },
+   };
+   return Err("do what".to_string());
 }
 
 pub fn build_input_engine_device_rusb(cfg: &Engine) -> Result<Box<dyn InputEngine>, String> {