Gunicorn fails to run without `futures`

[robbles]

Installing gunicorn 19.4.5 on OSX in a python 2.7 virtualenv yields the following error when I try to run it:

Error: class uri 'gunicorn.workers.gthread.ThreadWorker' invalid or not found:

[Traceback (most recent call last):
  File "/src/.venv/lib/python2.7/site-packages/gunicorn/util.py", line 142, in load_class
    mod = import_module('.'.join(components))
  File "/usr/local/Cellar/python/2.7.8_1/Frameworks/Python.framework/Versions/2.7/lib/python2.7/importlib/__init__.py", line 37, in import_module
    __import__(name)
  File "/src/.venv/lib/python2.7/site-packages/gunicorn/workers/gthread.py", line 37, in <module>
    """)
RuntimeError:
    You need to install the 'futures' package to use this worker with this
    Python version.

]

Installing futures with pip install futures seems to fix the problem. There's no explanation of this in the README though, it just says pip install gunicorn is enough. Did I miss a step, or is there a missing dependency that's not being pulled in on install?

[benoitc]

Using python 3 skips the need to install the futures packages :)

In the mean time we should probably add a note to the doc too, you're right. I will patch it ASAP or if you want don't hesitate to send a patch. Thanks anyway 👍

[robbles]

@benoitc thanks for the quick response!

I think adding a note to the docs is enough. I'd send a PR, but it'll probably be more work for you than just changing it when you have time.

I suppose requiring one extra step to continue using python2.X is good motivation for people like me to get on with upgrading to 3.x 😄

[mouarfff]

Hello, maybe i'm stupid but i don't know how to solve this problem...

I tried to type "pip install futures" but it's not work, there is the same message

I'm on debian 9.5 with 4.9.0-8-amd64 kernel

[aycatakmaz]

Deleting gunicorn from everywehere and installing gunicorn3 worked for me:

sudo apt-get remove gunicorn
pip uninstall gunicorn
pip3 uninstall gunicorn
sudo apt-get install gunicorn3