pass through error when no language model is provided

gentle/language_model_transcribe.py

@@ -60,6 +60,8 @@ def align_progress(audio_f, transcript, proto_langdir, nnet_dir, want_progress=F
         os.unlink(gen_hclg_filename)
 
 def show_progress(tran, ms=None):
+    if tran.get("error"):
+        return tran
     if tran.get("preview") is not None:
         # Yield some partial information
         return {"preview": tran["preview"],
@@ -99,7 +101,9 @@ def _normal_transcribe(audio_f, proto_langdir, nnet_dir, want_progress=False):
         yield {
             "transcript": "",
             "words": [],
+            "error": "No transcript provided."
         }
+        return
 
     try:
         k = standard_kaldi.Kaldi(nnet_dir, hclg_path, proto_langdir)

serve.py

@@ -113,7 +113,18 @@ def save():
             want_progress=True)
         result = None
         for result in progress:
-            if result.get("preview") is not None:
+            if result.get("error") is not None:
+                status["status"] = "ERROR"
+                status["error"] = result["error"]
+
+                # Save the status so that errors are recovered on restart of the server
+                # XXX: This won't work, because the endpoint will override this file
+                # XXX(2): duplicated code.
+                with open(os.path.join(outdir, 'status.json'), 'w') as jsfile:
+                    json.dump(status, jsfile, indent=2)
+                return
+
+            elif result.get("preview") is not None:
                 status["message"] = result["preview"]
                 status["t"] = result["t"]
             else: