tests: improve debug-trezor detection

should (finally) work with a connected production Trezor and an
emulator, in which case it should pick the emulator by itself

tests/device_tests/conftest.py

@@ -30,23 +30,23 @@ TREZOR_VERSION = None
 
 def get_device():
     path = os.environ.get("TREZOR_PATH")
+    interact = int(os.environ.get("INTERACT", 0))
     if path:
-        transport = get_transport(path)
+        try:
+            transport = get_transport(path)
+            return TrezorClientDebugLink(transport, auto_interact=not interact)
+        except Exception as e:
+            raise RuntimeError("Failed to open debuglink for {}".format(path)) from e
+
     else:
         devices = enumerate_devices()
         for device in devices:
-            if hasattr(device, "find_debug"):
-                transport = device
-                break
+            try:
+                return TrezorClientDebugLink(device, auto_interact=not interact)
+            except Exception:
+                pass
         else:
             raise RuntimeError("No debuggable device found")
-    env_interactive = int(os.environ.get("INTERACT", 0))
-    try:
-        return TrezorClientDebugLink(transport, auto_interact=not env_interactive)
-    except Exception as e:
-        raise RuntimeError(
-            "Failed to open debuglink for {}".format(transport.get_path())
-        ) from e
 
 
 def device_version():