Add log to gsutil fetch. (#1411)

Author: jonsimantov

Diff for: scripts/gha/integration_testing/ftl_gha_validator.py

@@ -79,7 +79,18 @@ def _gcs_list_dir(gcs_path):
   """Recursively returns a list of contents for a directory on GCS."""
   args = [GSUTIL, "ls", "-r", gcs_path]
   logging.info("Listing GCS contents: %s", " ".join(args))
-  result = subprocess.run(args=args, capture_output=True, text=True, check=True)
+  try:
+    result = subprocess.run(args=args, capture_output=True, text=True, check=True)
+  except subprocess.CalledProcessError as e:
+    # It's possible to have a CalledProcessError but still have gotten a file list.
+    # Check the stdout to see if we got lines that look GCS file paths, and ignore
+    # the error if so.
+    output = e.output.splitlines()
+    if len(output) > 1 and gcs_path in output[0]:
+      return output
+    else:
+      print("Error: %s" % e.stderr)
+      raise e
   return result.stdout.splitlines()
 
 
@@ -88,7 +99,11 @@ def _gcs_read_file(gcs_path):
   """Extracts the contents of a file on GCS."""
   args = [GSUTIL, "cat", gcs_path]
   logging.info("Reading GCS file: %s", " ".join(args))
-  result = subprocess.run(args=args, capture_output=True, text=True, check=True)
+  try:
+    result = subprocess.run(args=args, capture_output=True, text=True, check=True)
+  except subprocess.CalledProcessError as e:
+    print("Error: %s" % e.stderr)
+    raise e
   return result.stdout