[issue21691] set() returns random output with Python 3.4.1, in non-interactive mode

[Jackson Cooper]

New submission from Jackson Cooper:

The set() built-in returns random output, only when Python 3 is being used, and in non-interactive mode (executing a file).

Steps to reproduce:

1. Create file with only print(set(['A', 'B'])) inside it.

2. Execute file with Python 3.4.1 numerous times (10+) over 10+ seconds. The output will vary (randomly?) between {'B', 'A'} and {'A', 'B'}.


I can only reproduce this with Python 3.4.1 (have not tried 3.5). It cannot be reproduced in Python 2 (2.7.6) interactive or non-interactive mode, or Python 3.4.1 in interactive mode. Only in Python 3 when executing a file.


Tested on OS X 10.9.3, Python installed via Homebrew.

----------
components: Interpreter Core
messages: 220021
nosy: Jackson.Cooper
priority: normal
severity: normal
status: open
title: set() returns random output with Python 3.4.1, in non-interactive mode
type: behavior
versions: Python 3.4

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue21691>
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