diff --git a/flaml/automl/automl.py b/flaml/automl/automl.py
index 74b8741ac..1b6bef199 100644
--- a/flaml/automl/automl.py
+++ b/flaml/automl/automl.py
@@ -2604,11 +2604,12 @@ class AutoML(BaseEstimator):
         min_sample_size = min_sample_size or self._settings.get("min_sample_size")
         use_ray = self._settings.get("use_ray") if use_ray is None else use_ray
         use_spark = self._settings.get("use_spark") if use_spark is None else use_spark
-        spark_available, spark_error_msg = check_spark()
         if use_spark and use_ray is not False:
             raise ValueError("use_spark and use_ray cannot be both True.")
-        elif use_spark and not spark_available:
-            raise spark_error_msg
+        elif use_spark:
+            spark_available, spark_error_msg = check_spark()
+            if not spark_available:
+                raise spark_error_msg
 
         old_level = logger.getEffectiveLevel()
         self.verbose = verbose
@@ -2626,18 +2627,20 @@ class AutoML(BaseEstimator):
                     "Ray installed, setting use_ray to True. If you want to use Spark, set use_spark to True."
                 )
                 use_ray = True
-            elif spark_available:
-                logger.warning(
-                    "n_concurrent_trials > 1 is only supported when using Ray or Spark. "
-                    "Spark installed, setting use_spark to True. If you want to use Ray, set use_ray to True."
-                )
-                use_spark = True
             else:
-                logger.warning(
-                    "n_concurrent_trials > 1 is only supported when using Ray or Spark. "
-                    "Neither Ray nor Spark installed, setting n_concurrent_trials to 1."
-                )
-                n_concurrent_trials = 1
+                spark_available, _ = check_spark()
+                if spark_available:
+                    logger.warning(
+                        "n_concurrent_trials > 1 is only supported when using Ray or Spark. "
+                        "Spark installed, setting use_spark to True. If you want to use Ray, set use_ray to True."
+                    )
+                    use_spark = True
+                else:
+                    logger.warning(
+                        "n_concurrent_trials > 1 is only supported when using Ray or Spark. "
+                        "Neither Ray nor Spark installed, setting n_concurrent_trials to 1."
+                    )
+                    n_concurrent_trials = 1
 
         self._state.n_jobs = n_jobs
         self._n_concurrent_trials = n_concurrent_trials
diff --git a/flaml/tune/searcher/blendsearch.py b/flaml/tune/searcher/blendsearch.py
index 95f5d2fae..d091df9c7 100644
--- a/flaml/tune/searcher/blendsearch.py
+++ b/flaml/tune/searcher/blendsearch.py
@@ -90,7 +90,8 @@ class BlendSearch(Searcher):
                 needing to re-compute the trial. Must be the same or shorter length than
                 points_to_evaluate. When provided, `mode` must be specified.
             time_budget_s: int or float | Time budget in seconds.
-            num_samples: int | The number of configs to try.
+            num_samples: int | The number of configs to try. -1 means no limit on the
+                number of configs to try.
             resource_attr: A string to specify the resource dimension and the best
                 performance is assumed to be at the max_resource.
             min_resource: A float of the minimal resource to use for the resource_attr.
@@ -222,11 +223,12 @@ class BlendSearch(Searcher):
             else:
                 gs_space = space
             gs_seed = seed - 10 if (seed - 10) >= 0 else seed - 11 + (1 << 32)
+            self._gs_seed = gs_seed
             if experimental:
                 import optuna as ot
 
                 sampler = ot.samplers.TPESampler(
-                    seed=seed, multivariate=True, group=True
+                    seed=gs_seed, multivariate=True, group=True
                 )
             else:
                 sampler = None
@@ -306,7 +308,7 @@ class BlendSearch(Searcher):
                         space=self._gs._space,
                         metric=metric,
                         mode=mode,
-                        sampler=self._gs._sampler,
+                        seed=self._gs_seed,
                     )
                     self._gs.space = self._ls.space
                 self._init_search()
@@ -322,11 +324,12 @@ class BlendSearch(Searcher):
                     self.cost_attr = self._ls.cost_attr = TIME_TOTAL_S
             if "metric_target" in spec:
                 self._metric_target = spec.get("metric_target")
-            if "num_samples" in spec:
+            num_samples = spec.get("num_samples")
+            if num_samples is not None:
                 self._num_samples = (
-                    spec["num_samples"]
-                    + len(self._result)
-                    + len(self._trial_proposed_by)
+                    (num_samples + len(self._result) + len(self._trial_proposed_by))
+                    if num_samples > 0  # 0 is currently treated the same as -1
+                    else num_samples
                 )
         return True
 
diff --git a/flaml/tune/space.py b/flaml/tune/space.py
index a6b5090e7..f2200aceb 100644
--- a/flaml/tune/space.py
+++ b/flaml/tune/space.py
@@ -547,8 +547,8 @@ def complete_config(
                     domain.categories[index],
                     flow2,
                     disturb,
-                    lower and lower[key][index],
-                    upper and upper[key][index],
+                    lower and lower.get(key) and lower[key][index],
+                    upper and upper.get(key) and upper[key][index],
                 )
                 assert (
                     "_choice_" not in subspace[key]
@@ -560,8 +560,8 @@ def complete_config(
                     space[key],
                     flow2,
                     disturb,
-                    lower and lower[key],
-                    upper and upper[key],
+                    lower and lower.get(key),
+                    upper and upper.get(key),
                 )
             continue
         subspace[key] = domain
diff --git a/flaml/tune/spark/utils.py b/flaml/tune/spark/utils.py
index 03337c59b..142c42381 100644
--- a/flaml/tune/spark/utils.py
+++ b/flaml/tune/spark/utils.py
@@ -31,23 +31,21 @@ def check_spark():
         Return (True, None) if the check passes, otherwise log the exception message and
         return (False, Exception(msg)). The exception can be raised by the caller.
     """
-    logger.warning("\ncheck Spark installation...This line should appear only once.\n")
+    logger.debug("\ncheck Spark installation...This line should appear only once.\n")
     if not _have_spark:
         msg = """use_spark=True requires installation of PySpark. Please run pip install flaml[spark]
         and check [here](https://spark.apache.org/docs/latest/api/python/getting_started/install.html)
         for more details about installing Spark."""
-        logger.warning(msg)
         return False, ImportError(msg)
 
     if _spark_major_minor_version[0] < 3:
         msg = "Spark version must be >= 3.0 to use flaml[spark]"
-        logger.warning(msg)
         return False, ImportError(msg)
 
     try:
         SparkSession.builder.getOrCreate()
     except RuntimeError as e:
-        logger.warning(f"\nSparkSession is not available: {e}\n")
+        # logger.warning(f"\nSparkSession is not available: {e}\n")
         return False, RuntimeError(e)
 
     return True, None
diff --git a/flaml/tune/trial_runner.py b/flaml/tune/trial_runner.py
index 8fe8185a7..59e9d0d03 100644
--- a/flaml/tune/trial_runner.py
+++ b/flaml/tune/trial_runner.py
@@ -30,7 +30,7 @@ class SimpleTrial(Trial):
         self.config = config or {}
         self.status = Trial.PENDING
         self.start_time = None
-        self.last_result = {}
+        self.last_result = None
         self.last_update_time = -float("inf")
         self.custom_trial_name = None
         self.trainable_name = "trainable"
diff --git a/flaml/tune/tune.py b/flaml/tune/tune.py
index dabdf1a7c..47f6fa079 100644
--- a/flaml/tune/tune.py
+++ b/flaml/tune/tune.py
@@ -470,7 +470,9 @@ def run(
             logger.addHandler(old_handlers[0])
         if verbose > 0:
             if log_file_name:
-                os.makedirs(os.path.dirname(log_file_name), exist_ok=True)
+                dir_name = os.path.dirname(log_file_name)
+                if dir_name:
+                    os.makedirs(dir_name, exist_ok=True)
                 logger.addHandler(logging.FileHandler(log_file_name))
             elif not logger.hasHandlers():
                 # Add the console handler.
@@ -811,6 +813,10 @@ def run(
                         report(_metric=result)
                 _runner.stop_trial(trial_to_run)
                 num_failures = 0
+                if trial_to_run.last_result is None:
+                    # application stops tuning by returning None
+                    # TODO document this feature when it is finalized
+                    break
             else:
                 # break with upperbound_num_failures consecutive failures
                 num_failures += 1
diff --git a/flaml/version.py b/flaml/version.py
index 6849410aa..72f26f596 100644
--- a/flaml/version.py
+++ b/flaml/version.py
@@ -1 +1 @@
-__version__ = "1.1.0"
+__version__ = "1.1.2"
diff --git a/notebook/automl_classification.ipynb b/notebook/automl_classification.ipynb
index 86a6eb199..3d0561d3f 100644
--- a/notebook/automl_classification.ipynb
+++ b/notebook/automl_classification.ipynb
@@ -1,6 +1,7 @@
 {
  "cells": [
   {
+   "attachments": {},
    "cell_type": "markdown",
    "metadata": {
     "slideshow": {
@@ -38,10 +39,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "%pip install flaml[notebook]\n",
-    "# From v0.6.6, catboost is made an optional dependency to build conda package.\n",
-    "# To install catboost, you can run:\n",
-    "# %pip install flaml[catboost]"
+    "# %pip install flaml[notebook]"
    ]
   },
   {
@@ -749,7 +747,8 @@
     "xgb = XGBClassifier()\n",
     "cat_columns = X_train.select_dtypes(include=['category']).columns\n",
     "X = X_train.copy()\n",
-    "X[cat_columns] = X[cat_columns].apply(lambda x: x.cat.codes)\n"
+    "X[cat_columns] = X[cat_columns].apply(lambda x: x.cat.codes)\n",
+    "y_train_xgb = y_train.astype(\"int\")"
    ]
   },
   {
@@ -758,7 +757,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "xgb.fit(X, y_train)"
+    "xgb.fit(X, y_train_xgb)"
    ]
   },
   {
@@ -769,7 +768,8 @@
    "source": [
     "X = X_test.copy()\n",
     "X[cat_columns] = X[cat_columns].apply(lambda x: x.cat.codes)\n",
-    "y_pred_xgb = xgb.predict(X)"
+    "y_pred_xgb = xgb.predict(X)\n",
+    "y_test_xgb = y_test.astype(\"int\")\n"
    ]
   },
   {
@@ -788,7 +788,7 @@
     }
    ],
    "source": [
-    "print('default xgboost accuracy', '=', 1 - sklearn_metric_loss_score('accuracy', y_pred_xgb, y_test))\n",
+    "print('default xgboost accuracy', '=', 1 - sklearn_metric_loss_score('accuracy', y_pred_xgb, y_test_xgb))\n",
     "print('default lgbm accuracy', '=', 1 - sklearn_metric_loss_score('accuracy', y_pred_lgbm, y_test))\n",
     "print('flaml (10 min) accuracy', '=', 1 - sklearn_metric_loss_score('accuracy', y_pred, y_test))"
    ]
@@ -1283,7 +1283,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.9.15"
+   "version": "3.9.15 (main, Oct 26 2022, 03:47:43) \n[GCC 10.2.1 20210110]"
   },
   "vscode": {
    "interpreter": {
diff --git a/notebook/zeroshot_lightgbm.ipynb b/notebook/zeroshot_lightgbm.ipynb
index c5cb63783..bd43b4311 100644
--- a/notebook/zeroshot_lightgbm.ipynb
+++ b/notebook/zeroshot_lightgbm.ipynb
@@ -28,7 +28,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "%pip install -U flaml openml;"
+    "# %pip install -U flaml openml;"
    ]
   },
   {
@@ -520,7 +520,7 @@
     "    \"task\": \"regression\",\n",
     "    \"starting_points\": \"data\",\n",
     "    \"estimator_list\": [\"lgbm\"],\n",
-    "    \"time_budget\": 600,\n",
+    "    \"time_budget\": 300,\n",
     "}\n",
     "automl.fit(X_train, y_train, **settings)"
    ]
@@ -545,7 +545,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.9.7"
+   "version": "3.9.15 (main, Oct 26 2022, 03:47:43) \n[GCC 10.2.1 20210110]"
   }
  },
  "nbformat": 4,
diff --git a/setup.py b/setup.py
index 82ca7c501..fbb0ec2e7 100644
--- a/setup.py
+++ b/setup.py
@@ -75,6 +75,7 @@ setuptools.setup(
             "joblibspark>=0.5.0",
             "nbconvert",
             "nbformat",
+            "ipykernel",
         ],
         "catboost": ["catboost>=0.26"],
         "blendsearch": ["optuna==2.8.0"],
diff --git a/test/automl/test_notebook.py b/test/automl/test_notebook.py
new file mode 100644
index 000000000..e8f90d347
--- /dev/null
+++ b/test/automl/test_notebook.py
@@ -0,0 +1,45 @@
+import nbformat
+from nbconvert.preprocessors import ExecutePreprocessor
+from nbconvert.preprocessors import CellExecutionError
+import os
+import sys
+import pytest
+
+
+here = os.path.abspath(os.path.dirname(__file__))
+
+
+def run_notebook(input_nb, output_nb="executed_notebook.ipynb", save=False):
+    try:
+        file_path = os.path.join(here, os.pardir, os.pardir, "notebook", input_nb)
+        with open(file_path) as f:
+            nb = nbformat.read(f, as_version=4)
+        ep = ExecutePreprocessor(timeout=3600, kernel_name="python3")
+        ep.preprocess(nb, {"metadata": {"path": here}})
+    except CellExecutionError:
+        raise
+    finally:
+        if save:
+            with open(os.path.join(here, output_nb), "w", encoding="utf-8") as f:
+                nbformat.write(nb, f)
+
+
+@pytest.mark.skipif(
+    sys.platform != "darwin" or "3.8" not in sys.version,
+    reason="Only run on macOS with Python 3.8",
+)
+def test_automl_classification(save=False):
+    run_notebook("automl_classification.ipynb", save=save)
+
+
+@pytest.mark.skipif(
+    sys.platform != "darwin" or "3.7" not in sys.version,
+    reason="Only run on macOS with Python 3.7",
+)
+def test_zeroshot_lightgbm(save=False):
+    run_notebook("zeroshot_lightgbm.ipynb", save=save)
+
+
+if __name__ == "__main__":
+    # test_automl_classification(save=True)
+    test_zeroshot_lightgbm(save=True)
diff --git a/test/spark/test_notebook.py b/test/spark/test_notebook.py
index d900d76f7..2065a097a 100644
--- a/test/spark/test_notebook.py
+++ b/test/spark/test_notebook.py
@@ -25,8 +25,8 @@ def run_notebook(input_nb, output_nb="executed_notebook.ipynb", save=False):
         ep.preprocess(nb, {"metadata": {"path": here}})
     except CellExecutionError:
         raise
-    except Exception as e:
-        print("\nIgnoring below error:\n", e, "\n\n")
+    # except Exception as e:
+    #     print("\nIgnoring below error:\n", e, "\n\n")
     finally:
         if save:
             with open(os.path.join(here, output_nb), "w", encoding="utf-8") as f:
diff --git a/test/tune/test_reproducibility.py b/test/tune/test_reproducibility.py
index 974bdfd57..0c68a9136 100644
--- a/test/tune/test_reproducibility.py
+++ b/test/tune/test_reproducibility.py
@@ -34,7 +34,7 @@ def test_tune(externally_setup_searcher=False, use_ray=False, use_raytune=False)
         "width": tune.uniform(0, 20),
         "height": tune.uniform(-100, 100),
     }
-    if externally_setup_searcher:
+    if externally_setup_searcher is True:
 
         searcher = BlendSearch(
             space=search_space,
@@ -84,8 +84,10 @@ def test_tune(externally_setup_searcher=False, use_ray=False, use_raytune=False)
             metric="mean_loss",
             mode="min",
         )
-    else:
+    elif externally_setup_searcher is False:
         searcher = None
+    else:
+        searcher = externally_setup_searcher
 
     analysis = tune.run(
         easy_objective_custom_tune,
@@ -120,5 +122,19 @@ def test_reproducibility():
     ), "flaml.tune not reproducible when the searcher is set up externally"
 
 
+def test_gs_reproducibility():
+    from flaml import BlendSearch, tune
+
+    def f(config):
+        return {"m": 0.35}
+
+    search_space = {"a": tune.randint(1, 100)}
+    bs = BlendSearch(space=search_space, cost_attr=None)
+    analysis1 = tune.run(f, search_alg=bs, num_samples=2, metric="m", mode="max")
+    bs = BlendSearch(space=search_space, cost_attr=None)
+    analysis2 = tune.run(f, search_alg=bs, num_samples=2, metric="m", mode="max")
+    assert analysis1.trials[-1].config == analysis2.trials[-1].config
+
+
 if __name__ == "__main__":
     test_reproducibility()
diff --git a/test/tune/test_space.py b/test/tune/test_space.py
index 0081d1ffb..3192db875 100644
--- a/test/tune/test_space.py
+++ b/test/tune/test_space.py
@@ -66,6 +66,14 @@ def test_define_by_run():
         cfo.suggest(f"t{i}")
     # print(normalize(config, bs._gs.space, config, {}, False))
     print(complete_config({}, cfo._ls.space, cfo._ls))
+    # test hierarchical space with low_cost_partial_config
+    bs = BlendSearch(
+        space={"c": tune.choice([0, choice]), "randn": tune.randn(10, 2)},
+        low_cost_partial_config={"randn": 10},
+        metric="metric",
+        mode="max",
+    )
+    tune.run(lambda config: {"metric": 1}, search_alg=bs)
 
 
 def test_grid():
diff --git a/test/tune/test_stop.py b/test/tune/test_stop.py
new file mode 100644
index 000000000..49292df8a
--- /dev/null
+++ b/test/tune/test_stop.py
@@ -0,0 +1,25 @@
+from flaml import tune
+
+n_trials = 0
+
+
+def evaluate_config(config):
+    global n_trials
+    n_trials += 1
+    if n_trials >= 10:
+        return None
+    metric = (round(config["x"]) - 85000) ** 2 - config["x"] / config["y"]
+    return metric
+
+
+def test_eval_stop():
+    analysis = tune.run(
+        evaluate_config,
+        config={
+            "x": tune.qloguniform(lower=1, upper=100000, q=1),
+            "y": tune.qlograndint(lower=2, upper=100000, q=2),
+        },
+        num_samples=100,
+        mode="max",
+    )
+    assert len(analysis.trials) == 10
diff --git a/website/yarn.lock b/website/yarn.lock
index 8a7938635..3de8ad7bb 100644
--- a/website/yarn.lock
+++ b/website/yarn.lock
@@ -5085,9 +5085,9 @@ json-schema-traverse@^1.0.0:
   integrity sha512-NM8/P9n3XjXhIZn1lLhkFaACTOURQXjWhV4BA/RnOv8xvgqtqpAX9IO4mRQxSx1Rlo4tqzeqb0sOlruaOy3dug==
 
 json5@^2.1.2, json5@^2.2.1:
-  version "2.2.1"
-  resolved "https://registry.npmmirror.com/json5/-/json5-2.2.1.tgz#655d50ed1e6f95ad1a3caababd2b0efda10b395c"
-  integrity sha512-1hqLFMSrGHRHxav9q9gNjJ5EXznIxGVO09xQRrwplcS8qs28pZ8s8hupZAmqDwZUmVZ2Qb2jnyPOWcDH8m8dlA==
+  version "2.2.3"
+  resolved "https://registry.yarnpkg.com/json5/-/json5-2.2.3.tgz#78cd6f1a19bdc12b73db5ad0c61efd66c1e29283"
+  integrity sha512-XmOWe7eyHYH14cLdVPoyg+GOH3rYX++KpzrylJwSW98t3Nk+U8XOl8FWKOgwtzdb8lXGf6zYwDUzeHMWfxasyg==
 
 jsonfile@^6.0.1:
   version "6.1.0"