close_fds is not supported on Windows platforms if you redirect stdin/stdout/stderr

[flystar233]

close_fds is not supported on Windows platforms if you redirect stdin/stdout/stderr

[vm-asd2015]

I encounter the same problem.
Below is more information about the issue:

Webserver traceback log

(base) C:\Users\myusername>excalibur webserver
 * Serving Flask app "excalibur.www.app" (lazy loading)
 * Environment: production
   WARNING: Do not use the development server in a production environment.
   Use a production WSGI server instead.
 * Debug mode: off
 * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
127.0.0.1 - - [08/Feb/2019 09:55:45] "GET / HTTP/1.1" 302 -
127.0.0.1 - - [08/Feb/2019 09:55:45] "GET /files HTTP/1.1" 200 -
127.0.0.1 - - [08/Feb/2019 09:55:46] "GET /static/css/base.css HTTP/1.1" 304 -
127.0.0.1 - - [08/Feb/2019 09:55:46] "GET /static/js/vendor/popper.min.js HTTP/1.1" 304 -
127.0.0.1 - - [08/Feb/2019 09:55:46] "GET /static/css/vendor/bootstrap.min.css HTTP/1.1" 304 -
127.0.0.1 - - [08/Feb/2019 09:55:46] "GET /static/js/vendor/jquery-3.3.1.min.js HTTP/1.1" 304 -
127.0.0.1 - - [08/Feb/2019 09:55:46] "GET /static/js/vendor/bootstrap.min.js HTTP/1.1" 304 -
127.0.0.1 - - [08/Feb/2019 09:55:46] "GET /static/js/files.js HTTP/1.1" 304 - 127.0.0.1 - - [08/Feb/2019 09:55:47] "GET /static/favicon.ico HTTP/1.1" 200 -
127.0.0.1 - - [08/Feb/2019 09:56:02] "POST /files HTTP/1.1" 200 - 127.0.0.1 - - [08/Feb/2019 09:56:02] "GET /workspaces/e82d55e3-6832-447c-b0de-255d519d8c90 HTTP/1.1" 200 -
127.0.0.1 - - [08/Feb/2019 09:56:02] "GET /static/css/vendor/fontawesome.css HTTP/1.1" 200 -
127.0.0.1 - - [08/Feb/2019 09:56:02] "GET /static/css/vendor/jquery.selectareas.css HTTP/1.1" 200 -
127.0.0.1 - - [08/Feb/2019 09:56:02] "GET /static/css/workspace.css HTTP/1.1" 200 -
127.0.0.1 - - [08/Feb/2019 09:56:02] "GET /static/css/vendor/jquery-ui.structure.min.css HTTP/1.1" 200 -
127.0.0.1 - - [08/Feb/2019 09:56:02] "GET /static/css/vendor/jquery-ui.theme.min.css HTTP/1.1" 200 -
127.0.0.1 - - [08/Feb/2019 09:56:02] "GET /static/css/vendor/jquery-ui.min.css HTTP/1.1" 200 -
127.0.0.1 - - [08/Feb/2019 09:56:02] "GET /static/js/vendor/jquery.selectareas.min.js HTTP/1.1" 304 -
127.0.0.1 - - [08/Feb/2019 09:56:03] "GET /static/js/workspace.js HTTP/1.1" 304-
127.0.0.1 - - [08/Feb/2019 09:56:03] "GET /static/js/vendor/jquery-ui.min.js HTTP/1.1" 304 -
Traceback (most recent call last):
  File "c:\users\myusername\appdata\local\continuum\anaconda3\lib\site-packages\excalibur\executors\sequential_executor.py", line 12, in execute_command
    subprocess.check_call(command, stderr=subprocess.STDOUT, close_fds=True)
  File "c:\users\myusername\appdata\local\continuum\anaconda3\lib\subprocess.py",
line 286, in check_call
    retcode = call(*popenargs, **kwargs)
  File "c:\users\myusername\appdata\local\continuum\anaconda3\lib\subprocess.py",
line 267, in call
    with Popen(*popenargs, **kwargs) as p:
  File "c:\users\myusername\appdata\local\continuum\anaconda3\lib\subprocess.py",
line 624, in __init__
    "close_fds is not supported on Windows platforms"
ValueError: close_fds is not supported on Windows platforms if you redirect stdin/stdout/stderr

Version information

(base) C:\Users\myusername>python
Python 3.6.4 |Anaconda, Inc.| (default, Jan 16 2018, 10:22:32) [MSC v.1900 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import platform; print(platform.platform())
Windows-7-6.1.7601-SP1
>>> import sys; print('Python', sys.version)
Python 3.6.4 |Anaconda, Inc.| (default, Jan 16 2018, 10:22:32) [MSC v.1900 64 bit (AMD64)]
>>> import numpy; print('NumPy', numpy.__version__)
NumPy 1.14.2
>>> import cv2; print('OpenCV', cv2.__version__)
OpenCV 4.0.0
>>> import excalibur; print('Excalibur', excalibur.__version__)
Excalibur 0.4.2

[vm-asd2015]

I've just found another project's solution to this issue here.

[vinayak-mehta]

@vm-asd2015 Would you like to open a PR?

[Sijiu]

great!

[zhengyyi]

after I change the code according to close_fds incompatibility on windows platform, I encounter this problem:

GPL Ghostscript 9.52: Unrecoverable error, exit code 1
ERROR:root:-100
Traceback (most recent call last):
  File "C:\Users\zheng\Documents\lenovoJob\project file\excalibur\excalibur\executors\sequential_executor.py", line 13, in execute_command
    subprocess.check_call(command, stderr=subprocess.STDOUT, close_fds=(sys.platform != 'win32'))
  File "C:\Users\zheng\Anaconda3\envs\excalibur\lib\subprocess.py", line 306, in check_call
    retcode = call(*popenargs, **kwargs)
  File "C:\Users\zheng\Anaconda3\envs\excalibur\lib\subprocess.py", line 287, in call
    with Popen(*popenargs, **kwargs) as p:
  File "C:\Users\zheng\Anaconda3\envs\excalibur\lib\subprocess.py", line 729, in __init__
    restore_signals, start_new_session)
  File "C:\Users\zheng\Anaconda3\envs\excalibur\lib\subprocess.py", line 1017, in _execute_child
    startupinfo)
FileNotFoundError: [WinError 2] The system cannot find the specified file

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\zheng\Documents\lenovoJob\project file\excalibur\excalibur\tasks.py", line 77, in split
    with Ghostscript(*gs_call, stdout=null) as gs:
  File "C:\Users\zheng\Documents\lenovoJob\project file\excalibur\excalibur\camelot\ext\ghostscript\__init__.py", line 95, in Ghostscript
    stderr=kwargs.get("stderr", None),
  File "C:\Users\zheng\Documents\lenovoJob\project file\excalibur\excalibur\camelot\ext\ghostscript\__init__.py", line 39, in __init__
    rc = gs.init_with_args(instance, args)
  File "C:\Users\zheng\Documents\lenovoJob\project file\excalibur\excalibur\camelot\ext\ghostscript\_gsprint.py", line 173, in init_with_args
    raise GhostscriptError(rc)
excalibur.camelot.ext.ghostscript._gsprint.GhostscriptError: -100