From bb449791b1cfd7bd60719b144e8dc3da89170785 Mon Sep 17 00:00:00 2001
From: Rhys Doyle <48983334+rdoyle45@users.noreply.github.com>
Date: Thu, 17 Oct 2019 10:55:14 +0100
Subject: [PATCH 1/5] Revert #3358

---
 xarray/backends/locks.py | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/xarray/backends/locks.py b/xarray/backends/locks.py
index d0bf790f074..551dffad38e 100644
--- a/xarray/backends/locks.py
+++ b/xarray/backends/locks.py
@@ -86,9 +86,10 @@ def _get_scheduler(get=None, collection=None):
     except (ImportError, AttributeError):
         pass
 
-    if actual_get is dask.multiprocessing.get:
-        return "multiprocessing"
-    else:
+    try:
+        if actual_get is dask.multiprocessing.get:
+            return "multiprocessing"
+    except (AttributeError):
         return "threaded"
 
 

From 5bd1c573b04a92fbc334548a7229c687e5c79017 Mon Sep 17 00:00:00 2001
From: Rhys Doyle <48983334+rdoyle45@users.noreply.github.com>
Date: Thu, 17 Oct 2019 11:16:24 +0100
Subject: [PATCH 2/5] Revision

---
 xarray/backends/locks.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/xarray/backends/locks.py b/xarray/backends/locks.py
index 551dffad38e..6722ced1353 100644
--- a/xarray/backends/locks.py
+++ b/xarray/backends/locks.py
@@ -89,6 +89,8 @@ def _get_scheduler(get=None, collection=None):
     try:
         if actual_get is dask.multiprocessing.get:
             return "multiprocessing"
+        else:
+            return "threaded"
     except (AttributeError):
         return "threaded"
 

From 7b7230b434419c0f06af7fb22434e9428893d2ab Mon Sep 17 00:00:00 2001
From: Guido Imperiale <crusaderky@gmail.com>
Date: Sun, 20 Oct 2019 10:48:20 +0100
Subject: [PATCH 3/5] Code review

---
 doc/whats-new.rst        |  6 ++++++
 xarray/backends/locks.py | 13 +++++++------
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/doc/whats-new.rst b/doc/whats-new.rst
index 2202c91408b..bf2959fba71 100644
--- a/doc/whats-new.rst
+++ b/doc/whats-new.rst
@@ -18,6 +18,11 @@ What's New
 v0.14.1 (unreleased)
 --------------------
 
+Bug fixes
+~~~~~~~~~
+- Fix regression introduced in v0.14.0 that would cause a crash if dask is installed
+  but cloudpickle isn't (:issue:`3401`) by `Rhys Doyle <https://github.com/rdoyle45>`_
+
 Documentation
 ~~~~~~~~~~~~~
 
@@ -26,6 +31,7 @@ Documentation
   datetime-like dimension is required. (:pull:`3400`)
   By `Justus Magin <https://github.com/keewis>`_.
 
+
 .. _whats-new.0.14.0:
 
 v0.14.0 (14 Oct 2019)
diff --git a/xarray/backends/locks.py b/xarray/backends/locks.py
index 6722ced1353..4b4edebf28c 100644
--- a/xarray/backends/locks.py
+++ b/xarray/backends/locks.py
@@ -1,7 +1,7 @@
 import multiprocessing
 import threading
 import weakref
-from typing import Any, MutableMapping
+from typing import Any, MutableMapping, Optional
 
 try:
     from dask.utils import SerializableLock
@@ -62,7 +62,7 @@ def _get_lock_maker(scheduler=None):
     return _LOCK_MAKERS[scheduler]
 
 
-def _get_scheduler(get=None, collection=None):
+def _get_scheduler(get=None, collection=None) -> Optional[str]:
     """Determine the dask scheduler that is being used.
 
     None is returned if no dask scheduler is active.
@@ -87,12 +87,13 @@ def _get_scheduler(get=None, collection=None):
         pass
 
     try:
+        # dask.multiprocessing requires cloudpickle to be installed
         if actual_get is dask.multiprocessing.get:
             return "multiprocessing"
-        else:
-            return "threaded"
-    except (AttributeError):
-        return "threaded"
+    except AttributeError:
+        pass
+
+    return "threaded"
 
 
 def get_write_lock(key):

From f9616858f7b39ac63951e9d230583ec659df1d52 Mon Sep 17 00:00:00 2001
From: Guido Imperiale <crusaderky@gmail.com>
Date: Sun, 20 Oct 2019 10:49:14 +0100
Subject: [PATCH 4/5] Merge from master

---
 doc/whats-new.rst | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/doc/whats-new.rst b/doc/whats-new.rst
index f64102c94d0..ab9a0adc101 100644
--- a/doc/whats-new.rst
+++ b/doc/whats-new.rst
@@ -18,10 +18,6 @@ What's New
 v0.14.1 (unreleased)
 --------------------
 
-Bug fixes
-~~~~~~~~~
-- Fix regression introduced in v0.14.0 that would cause a crash if dask is installed
-  but cloudpickle isn't (:issue:`3401`) by `Rhys Doyle <https://github.com/rdoyle45>`_
 New Features
 ~~~~~~~~~~~~
 - Added integration tests against `pint <https://pint.readthedocs.io/>`_.
@@ -35,6 +31,11 @@ New Features
     ``pip install git+https://github.com/andrewgsavage/pint.git@refs/pull/6/head)``.
     Even with it, interaction with non-numpy array libraries, e.g. dask or sparse, is broken.
 
+Bug fixes
+~~~~~~~~~
+- Fix regression introduced in v0.14.0 that would cause a crash if dask is installed
+  but cloudpickle isn't (:issue:`3401`) by `Rhys Doyle <https://github.com/rdoyle45>`_
+
 Documentation
 ~~~~~~~~~~~~~
 

From df7bd893963d546ed7349b3a7409065b99c1adb9 Mon Sep 17 00:00:00 2001
From: Guido Imperiale <crusaderky@gmail.com>
Date: Sun, 20 Oct 2019 23:47:27 +0100
Subject: [PATCH 5/5] Obsolescence note

---
 xarray/backends/locks.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/xarray/backends/locks.py b/xarray/backends/locks.py
index 4b4edebf28c..435690f2079 100644
--- a/xarray/backends/locks.py
+++ b/xarray/backends/locks.py
@@ -87,7 +87,8 @@ def _get_scheduler(get=None, collection=None) -> Optional[str]:
         pass
 
     try:
-        # dask.multiprocessing requires cloudpickle to be installed
+        # As of dask=2.6, dask.multiprocessing requires cloudpickle to be installed
+        # Dependency removed in https://github.com/dask/dask/pull/5511
         if actual_get is dask.multiprocessing.get:
             return "multiprocessing"
     except AttributeError: