Fix CI errors.

.github/workflows/run-pretrained.yml

@@ -30,7 +30,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-18.04]
-        python-version: [3.6, 3.7, 3.8, 3.9]
+        python-version: [3.7, 3.8, 3.9]
         torch: ["1.10.0"]
         torchaudio: ["0.10.0"]
         k2-version: ["1.9.dev20211101"]

.github/workflows/test.yml

@@ -32,7 +32,7 @@ jobs:
         # os: [ubuntu-18.04, macos-10.15]
         # disable macOS test for now.
         os: [ubuntu-18.04]
-        python-version: [3.6, 3.7, 3.8, 3.9]
+        python-version: [3.7, 3.8]
         torch: ["1.8.0", "1.10.0"]
         torchaudio: ["0.8.0", "0.10.0"]
         k2-version: ["1.9.dev20211101"]
@@ -106,6 +106,12 @@ jobs:
           if [[ ${{ matrix.torchaudio }} == "0.10.0" ]]; then
             cd ../transducer
             pytest -v -s
+
+            cd ../transducer_stateless
+            pytest -v -s
+
+            cd ../transducer_lstm
+            pytest -v -s
           fi
 
       - name: Run tests
@@ -125,4 +131,10 @@ jobs:
           if [[ ${{ matrix.torchaudio }} == "0.10.0" ]]; then
             cd ../transducer
             pytest -v -s
+
+            cd ../transducer_stateless
+            pytest -v -s
+
+            cd ../transducer_lstm
+            pytest -v -s
           fi

egs/librispeech/ASR/README.md

@@ -13,5 +13,4 @@ The following table lists the differences among them.
 |------------------------|-----------|--------------------|
 | `transducer`           | Conformer | LSTM               |
 | `transducer_stateless` | Conformer | Conv1d + Embedding |
-
-
+| `transducer_lstm     ` | LSTM      | LSTM               |

egs/librispeech/ASR/transducer_stateless/test_decoder.py

@@ -23,8 +23,6 @@ To run this file, do:
 """
 
 import torch
-import torch.nn as nn
-import torch.nn.functional as F
 from decoder import Decoder