Windows support?

[chrizzFTD]

Hi, this looks like a great project!

I wanted to give it a try but after installing via pip install git+git://github.com/tgoodlet/tractor.git, importing tractor fails because forkserver seems to not be available on my os (windows10):

Python 3.7.2 (default, Feb 21 2019, 17:35:59) [MSC v.1915 64 bit (AMD64)] :: Anaconda, Inc. on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import tractor
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\ProgramData\Miniconda3\envs\tractor19030502\lib\site-packages\tractor\__init__.py", line 18, in <module>
    from ._trionics import open_nursery
  File "C:\ProgramData\Miniconda3\envs\tractor19030502\lib\site-packages\tractor\_trionics.py", line 21, in <module>
    ctx = mp.get_context("forkserver")
  File "C:\ProgramData\Miniconda3\envs\tractor19030502\lib\multiprocessing\context.py", line 238, in get_context
    return super().get_context(method)
  File "C:\ProgramData\Miniconda3\envs\tractor19030502\lib\multiprocessing\context.py", line 192, in get_context
    raise ValueError('cannot find context for %r' % method) from None
ValueError: cannot find context for 'forkserver'
>>>

Any plan on adding windows support in the future?

[goodboy]

Hey @chrizzFTD thanks for attempting to give it a try 😄

Yes, unfortunately no Windows support yet 😢
I don't really use windows at all but I definitely do want to add support!

It should be possible to use the spawn method from multiprocessing.
I've been meaning to try this out since it should work on linux as well.

You're very welcome to try and add it yourself though I have no idea it will work out of the box.
If you're not interested I could definitely use your help testing!

I've made #60 for that specific task and then hopefully adding it solves this 👍

[goodboy]

@chrizzFTD mind trying out #61's branch to see if it works for you on windows?

[chrizzFTD]

Yes, thank you so much for taking a look so quickly @tgoodlet 😃

I've left some updates on #61 (comment), but in short, the only issue I'm seeing is (because of the same windows deal):

trio.MultiError: AttributeError("module 'trio.hazmat' has no attribute 'wait_readable'"), AttributeError("module 'trio.hazmat' has no attribute 'wait_readable'")

I'm keen on helping testing as much as possible!

[goodboy]

I'm keen on helping testing as much as possible!

@chrizzFTD awesome!

because of the same windows deal

Indeed. I'll coordinate with you on #61.

[goodboy]

Hmm I wonder if part of solving this should be adding a CI job too.
Looks like travis started supporting it late last year!

Oof but no python support yet....

[goodboy]

@njsmith tipped me to free vms from microsoft for testing purposes as well.

[goodboy]

Just an update, as of #61 and #62 we do have working windows support both verified in manual testing by @chrizzFTD and now in travisCI.

There's still some kinks to work out (unreliable CI builds it seems) as well as some more documentation needed to get windows users working well with multiprocessing gotchas.

[goodboy]

The unreliable CI builds seem to be either a race condition in determining the "arbiter" actor or some weird issue with being unable to find the pip module?

I want to get #79 docs complete before considering this done as well.

[goodboy]

Also need to update the listed OS support in setup.py.