transcriberbin: panicks when created from gst-inspect

gst-inspect-1.0 -u
....
thread '<unnamed>' panicked at src/transcriberbin/imp.rs:1088:37:                                                                                                                                                  
called `Result::unwrap()` on an `Err` value: Failed to find element factory with name 'awstranscriber' for creating element                                                                                        
                                                                                                                                                                                                                   
Stack backtrace:                                                                                                                                                                                                   
   0: anyhow::error::<impl core::convert::From<E> for anyhow::Error>::from                                                                                                                                         
   1: <gstrsclosedcaption::transcriberbin::imp::TranscriberSinkPad as glib::subclass::types::ObjectSubclass>::new                                                                                                  
   2: glib::subclass::types::instance_init                                                                                                                                                                         
   3: g_type_create_instance                                                                                                                                                                                       
   4: <unknown>                                                                                                                                                                                                    
   5: g_object_new_with_properties                                                                                                                                                                                 
   6: glib::object::Object::new_internal                                                                                                                                                                           
   7: gstreamer::pad::PadBuilder<T>::from_template                                                                                                                                                                 
   8: <gstrsclosedcaption::transcriberbin::imp::TranscriberBin as glib::subclass::types::ObjectSubclass>::with_class                                                                                               
   9: glib::subclass::types::instance_init                                                                                                                                                                         
  10: g_type_create_instance                                                                                                                                                                                       
  11: <unknown>                                                                                                                                                                                                    
  12: g_object_new_with_properties                                                                                                                                                                                 
  13: gst_element_factory_create_with_properties                                                                                                                                                                   
             at /_build/../gstreamer/subprojects/gstreamer/gst/gstelementfactory.c:494:28