Intermediate changes

1 files changed, 15 insertions, 7 deletions

diff --git a/yt/python/yt/common.py b/yt/python/yt/common.py
index e2c96a80ff5..a3c2969125f 100644
--- a/yt/python/yt/common.py
+++ b/yt/python/yt/common.py
@@ -834,30 +834,34 @@ def wait(predicate, error_message=None, iter=None, sleep_backoff=None, timeout=N
     if sleep_backoff is None:
         sleep_backoff = 0.3
 
+    last_exception = None
     if ignore_exceptions:
         def check_predicate():
             try:
-                return predicate()
+                return predicate(), None
             # Do not catch BaseException because pytest exceptions are inherited from it
             # pytest.fail raises exception inherited from BaseException.
-            except Exception:
-                return False
+            except Exception as ex:
+                return False, ex
     else:
-        check_predicate = predicate
+        def check_predicate():
+            return predicate(), None
 
     if timeout is None:
         if iter is None:
             iter = 100
         index = 0
         while index < iter:
-            if check_predicate():
+            result, last_exception = check_predicate()
+            if result:
                 return
             index += 1
             time.sleep(sleep_backoff)
     else:
         start_time = datetime.datetime.now()
         while datetime.datetime.now() - start_time < datetime.timedelta(seconds=timeout):
-            if check_predicate():
+            result, last_exception = check_predicate()
+            if result:
                 return
             time.sleep(sleep_backoff)
 
@@ -865,5 +869,9 @@ def wait(predicate, error_message=None, iter=None, sleep_backoff=None, timeout=N
         error_message = error_message()
     if error_message is None:
         error_message = "Wait failed"
-    error_message += " (timeout = {0})".format(timeout if timeout is not None else iter * sleep_backoff)
+
+    error_message += f" (timeout = {timeout if timeout is not None else iter * sleep_backoff}"
+    if last_exception is not None:
+        error_message += f", exception = {last_exception}"
+    error_message += ")"
     raise WaitFailed(error_message)