Behave in parallel - windows

Question

I try to run behave tests in parallel. For this I use behave-parallel lib and demo project https://github.com/vishalm/behave_parallel_demo. But OS is Windows 10. After steps from Read_me file. I am getting next Tracebacks
(behave_parallel_demo-master) D:\Python_projects\behave_parallel_demo-master>behave --processes 5 --parallel-element feature
INFO: 0 scenario(s) and 3 feature(s) queued for consideration by 5 workers. Some may be skipped if the -t option was given...
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "c:\python27\Lib\multiprocessing\forking.py", line 381, in main
self = load(from_parent)
File "c:\python27\Lib\pickle.py", line 1384, in load
return Unpickler(file).load()
File "c:\python27\Lib\pickle.py", line 864, in load
dispatch[key](self)
File "c:\python27\Lib\pickle.py", line 1089, in load_newobj
obj = cls.__new__(cls, *args)
TypeError: __new__() takes exactly 3 arguments (2 given)
Traceback (most recent call last):
File "c:\python27\Lib\runpy.py", line 174, in _run_module_as_main
"__main__", fname, loader, pkg_name)
File "c:\python27\Lib\runpy.py", line 72, in _run_code
exec code in run_globals
File "C:\Users\Andriy_Petrenko\Envs\behave_parallel_demo-master\Scripts\behave.exe\__main__.py", line 9, in <module>
File "c:\users\andriy_petrenko\envs\behave_parallel_demo-master\lib\site-packages\behave\__main__.py", line 111, in main
failed = runner.run()
File "c:\users\andriy_petrenko\envs\behave_parallel_demo-master\lib\site-packages\behave\runner.py", line 561, in run
return self.run_with_paths()
File "c:\users\andriy_petrenko\envs\behave_parallel_demo-master\lib\site-packages\behave\runner.py", line 583, in run_with_paths
return self.run_multiproc()
File "c:\users\andriy_petrenko\envs\behave_parallel_demo-master\lib\site-packages\behave\runner.py", line 690, in run_multiproc
p.start()
File "c:\python27\Lib\multiprocessing\process.py", line 130, in start
self._popen = Popen(self)
File "c:\python27\Lib\multiprocessing\forking.py", line 280, in __init__
to_child.close()
IOError: [Errno 22] Invalid argument
What I do wrong or is this OS problem? It looks like that 5 workers were up but 1st problem is that TypeError: __new__() takes exactly 3 arguments (2 given) and 2nd IOError: [Errno 22] Invalid argument

Answer 1

I am not familiar with Behave so not sure whether you are passing the command line correctly but this error means that one of the method is expecting more arguments than you have provided. In this case, it's during creation of cls instance:
File "c:\python27\Lib\pickle.py", line 1089, in load_newobj
obj = cls.__new__(cls, *args)
This looks like some internal class instance so you do not control it directly so make sure you pass enough and correct arguments at command line.

Answer 2

Update your Behave package. it will work.

Answer 3

We have been trying for a long time to implement parallel test executions with behave (which is an amazing framework). Finally, we created our own wrapper on top of Behave, called BehaveX, that not only allow us to execute tests in parallel, but also comes with great reports and some additional features:
https://github.com/hrcorval/behavex
As BehaveX is implemented over the Behave framework, with this wrapper you should be able to replace the "behave" executable by "behavex", and run the tests in parallel using the following commands:
behavex -t #TAG --parallel-processes 4 --parallel-scheme scenario
behavex -t #TAG --parallel-processes 3 --parallel-scheme feature