Handle no backend exception: write warning

sgued · Jul 28, 2020 · 7fd8d3c · 7fd8d3c
1 parent 5b4022e
commit 7fd8d3c
Showing 1 changed file with 7 additions and 1 deletion.
diff --git a/pynitrokey/start/gnuk_token.py b/pynitrokey/start/gnuk_token.py
@@ -634,7 +634,13 @@ def gnuk_devices():
 
 
 def gnuk_devices_by_vidpid():
-    busses = usb.busses()
+    try:
+        busses = usb.busses()
+    except usb.core.NoBackendError:
+        print("Warning: no backend was found to use for communication. "
+              "Please refer to documentation how to install additional libraries.")
+        return []
+
     for bus in busses:
         devices = bus.devices
         for dev in devices: