Minor bug fixes

PiperOrigin-RevId: 422637653

official/core/base_task.py

@@ -101,9 +101,11 @@ class Task(tf.Module, metaclass=abc.ABCMeta):
     ckpt_dir_or_file = self.task_config.init_checkpoint
     logging.info("Trying to load pretrained checkpoint from %s",
                  ckpt_dir_or_file)
-    if tf.io.gfile.isdir(ckpt_dir_or_file):
+    if ckpt_dir_or_file and tf.io.gfile.isdir(ckpt_dir_or_file):
       ckpt_dir_or_file = tf.train.latest_checkpoint(ckpt_dir_or_file)
     if not ckpt_dir_or_file:
+      logging.info("No checkpoint file found from %s. Will not load.",
+                   ckpt_dir_or_file)
       return
 
     if hasattr(model, "checkpoint_items"):

official/nlp/tasks/dual_encoder.py

@@ -187,9 +187,13 @@ class DualEncoderTask(base_task.Task):
   def initialize(self, model):
     """Load a pretrained checkpoint (if exists) and then train from iter 0."""
     ckpt_dir_or_file = self.task_config.init_checkpoint
-    if tf.io.gfile.isdir(ckpt_dir_or_file):
+    logging.info('Trying to load pretrained checkpoint from %s',
+                 ckpt_dir_or_file)
+    if ckpt_dir_or_file and tf.io.gfile.isdir(ckpt_dir_or_file):
       ckpt_dir_or_file = tf.train.latest_checkpoint(ckpt_dir_or_file)
     if not ckpt_dir_or_file:
+      logging.info('No checkpoint file found from %s. Will not load.',
+                   ckpt_dir_or_file)
       return
 
     pretrain2finetune_mapping = {

official/nlp/tasks/sentence_prediction.py

@@ -223,10 +223,14 @@ class SentencePredictionTask(base_task.Task):
   def initialize(self, model):
     """Load a pretrained checkpoint (if exists) and then train from iter 0."""
     ckpt_dir_or_file = self.task_config.init_checkpoint
+    logging.info('Trying to load pretrained checkpoint from %s',
+                 ckpt_dir_or_file)
+    if ckpt_dir_or_file and tf.io.gfile.isdir(ckpt_dir_or_file):
+      ckpt_dir_or_file = tf.train.latest_checkpoint(ckpt_dir_or_file)
     if not ckpt_dir_or_file:
+      logging.info('No checkpoint file found from %s. Will not load.',
+                   ckpt_dir_or_file)
       return
-    if tf.io.gfile.isdir(ckpt_dir_or_file):
-      ckpt_dir_or_file = tf.train.latest_checkpoint(ckpt_dir_or_file)
 
     pretrain2finetune_mapping = {
         'encoder': model.checkpoint_items['encoder'],