curses not available on windows

[ltalirz]

As noticed in the circus feedstock on conda-forge, circus uses curses but it seems curses doesn't work on windows (?).

In this issue, it was mentioned that circus supports windows since version 0.12, so it seems like we are missing something.
How should we build the circus conda package for windows?

possible workarounds

• https://github.com/zephyrproject-rtos/windows-curses
• https://stackoverflow.com/a/41224335

Mentioning also the recipe maintainer @carlodri

[ltalirz]

It seems to me that the curses library is used in three lines of code only, using two functions:

circus/circus/stats/client.py

Line 89 in 6ca0d18

curses.endwin()

circus/circus/stats/client.py

Line 234 in 6ca0d18

stdscr = curses.initscr()

(introduced in commit 7d062b5 ).

Given that this currently blocks the windows build of circus on conda-forge, it would be great to understand whether this is really necessary or whether endwin() and initscr() can be replaced by something supported on windows.

Mentioning @tarekziade for comment (and @sphuber for info)

Edit: Fixed commit hash

[nuno-andre]

There are some wheels based on PDCurses to support curses library in Windows. It may help.

[ltalirz]

Thansk @nuno-andre

So, I guess the idea would be to

• add a feedstock for windows-curses on conda-forge
• let the circus feedstock depend on

 - windows-curses  [win]
 - curses  [not win]

Is it possible to create a conda-forge feedstock from a python wheel or does the wheel need to be built by conda?
Apparently you can with conda, just wondering whether there is an example of this on conda-forge...

[nuno-andre]

It think the best option would be to go with setuptools by adding the platform dependent requirement to setup.py:

install_requires = [
    'psutil', 
    'pyzmq>=17.0',
    'tornado>=3.0,<5.0',
    'six',
    'windows-curses>=2.10;platform_system=="Windows"',
]

This way both pip and conda will be able to install the wheels.

It may also be worth merging #1065 to get better Windows support.