Use multiprocess if available

On Windows, we force it to be installed as most users will need it.

CHANGES

@@ -1,4 +1,3 @@
-
 =======
 Changes
 =======
@@ -8,6 +7,7 @@ Changes
 
  - python 3.8 support
  - BACKWARD INCOMPATIBLE: Drop Python 3.4 support
+ - support `multiprocess` and require it for Windows
 
 
 0.32.0 (*2019-12-10*)
@@ -527,4 +527,3 @@ Changes
 ====================
 
 - initial release
-

doc/cmd_run.rst

@@ -240,6 +240,8 @@ parallel execution
 This allows different tasks to be run in parallel, as long any dependencies are met.
 By default the `multiprocessing <http://docs.python.org/library/multiprocessing.html>`_
 module is used.
+If the `multiprocess <https://pypi.org/project/multiprocess/>`_ module is installed,
+it will be used instead.
 So the same restrictions also apply to the use of multiprocessing in `doit`.
 
 .. code-block:: console

doit/cmd_auto.py

@@ -4,7 +4,10 @@
 import os
 import time
 import sys
-from multiprocessing import Process
+try:
+    from multiprocess import Process
+except ImportError:
+    from multiprocessing import Process
 from subprocess import call
 
 from .exceptions import InvalidCommand

doit/runner.py

@@ -1,6 +1,9 @@
 """Task runner"""
 
-from multiprocessing import Process, Queue as MQueue
+try:
+    from multiprocess import Process, Queue as MQueue
+except ImportError:
+    from multiprocessing import Process, Queue as MQueue
 from threading import Thread
 import pickle
 import queue

setup.py

@@ -81,6 +81,7 @@
       extras_require={
           ':sys.platform == "darwin"': ['macfsevents'],
           ':sys.platform == "linux"': ['pyinotify'],
+          ':sys.platform == "win32"': ['multiprocess'],
       },
       long_description = long_description,
       entry_points = {

tests/test_cmd_auto.py

@@ -1,5 +1,8 @@
 import time
-from multiprocessing import Process
+try:
+    from multiprocess import Process
+except ImportError:
+    from multiprocessing import Process
 
 import pytest
 

tests/test_runner.py

@@ -1,6 +1,9 @@
 import os
 import pickle
-from multiprocessing import Queue
+try:
+    from multiprocess import Queue
+except ImportError:
+    from multiprocessing import Queue
 import platform
 from unittest.mock import Mock