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Author daveb
Recipients daveb
Date 2019-07-10.17:52:05
SpamBayes Score -1.0
Marked as misclassified Yes
Message-id <>
os.dup(fd) generates an OSError for standard streams (0: stdin, 1: stdout, 2: stderr) on Windows 7.  Works as expected on Windows 10.

Working backwards we found the issue first appears in Python 3.7.4rc1 and 3.8.0b2 on Windows 7.  Earlier releases work as expected.

>>> import os
>>> os.dup(1)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
OSError: [WinError 87] The parameter is incorrect
Date User Action Args
2019-07-10 17:52:06davebsetrecipients: + daveb
2019-07-10 17:52:05davebsetmessageid: <>
2019-07-10 17:52:05daveblinkissue37549 messages
2019-07-10 17:52:05davebcreate