Bug in Python3 ('tempfile' and 'subprocess')

Bug in Python3 ('tempfile' and 'subprocess')

[Giuseppe Scelsi]

Hi,

Using freshly-updated Cygwin 64-bit under Windows 7 Enterprise Ver 6.1 
and Python 3 version 3.6.4.

Executing the following script:

     import subprocess
     import _hashlib
     import _sha3
     subprocess.run('pwd')

always results in 'BlockingIOError: [Errno 11] Resource temporarily
unavailable'.  I saw this error first in a script that imported
'tempfile' together with 'subprocess'.  I then managed to narrow down
the problem to the '_sha3' module.  Notice that you need to import both 
'_hashlib' and '_sha3' *in that order*.

This problem makes it impossible to use 'tempfile' and 'subprocess' in 
the same script.  My workaround is currently to disable '_sha3' in
'/usr/lib/python3.6/hashlib.py' by adding at line 62:

     __always_supported = __always_supported[0:8]

This problem only happens in Cygwin 64, 32-bit Cygwin works ok.

Can anyone reproduce this problem?

Best regards,

Giuseppe

--
Giuseppe B. Scelsi  (giuseppe.scelsi@analog.com)
Senior Design Engineer, Analog Devices Australia Pty Ltd
Unit 3, 97 Lewis Road, Wantirna, Victoria, 3152, AUSTRALIA
Direct: +61 3 9881 9909   Main: +61 3 9881 9999
Fax: +61 3 9881 9988      Web: www.analog.com/au

Embedded & Digital Signal Processing Software.

This communication is proprietary and confidential.

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