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sys.flags and sys.float_info disappear at shutdown #64801

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pitrou opened this issue Feb 11, 2014 · 10 comments
Closed

sys.flags and sys.float_info disappear at shutdown #64801

pitrou opened this issue Feb 11, 2014 · 10 comments
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3.7 (EOL) end of life 3.8 only security fixes interpreter-core (Objects, Python, Grammar, and Parser dirs) type-bug An unexpected behavior, bug, or error

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@pitrou
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pitrou commented Feb 11, 2014

BPO 20602
Nosy @pitrou, @vstinner, @tiran, @encukou, @serhiy-storchaka, @ZackerySpytz
PRs
  • bpo-20602: Do not clear sys.flags and sys.float_info during shutdown #8096
    		•
    Files
  • sys_at_exit.py
    		•

    Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.

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    GitHub fields:

    assignee = None
closed_at = <Date 2019-06-02.21:31:33.722>
created_at = <Date 2014-02-11.19:22:01.349>
labels = ['interpreter-core', '3.8', 'type-bug', '3.7']
title = 'sys.flags and sys.float_info disappear at shutdown'
updated_at = <Date 2019-06-02.21:31:33.721>
user = 'https://github.com/pitrou'

    bugs.python.org fields:

    activity = <Date 2019-06-02.21:31:33.721>
actor = 'vstinner'
assignee = 'none'
closed = True
closed_date = <Date 2019-06-02.21:31:33.722>
closer = 'vstinner'
components = ['Interpreter Core']
creation = <Date 2014-02-11.19:22:01.349>
creator = 'pitrou'
dependencies = []
files = ['38404']
hgrepos = []
issue_num = 20602
keywords = ['patch']
message_count = 10.0
messages = ['211001', '237604', '237617', '237620', '237621', '237622', '321071', '331426', '343970', '344323']
nosy_count = 6.0
nosy_names = ['pitrou', 'vstinner', 'christian.heimes', 'petr.viktorin', 'serhiy.storchaka', 'ZackerySpytz']
pr_nums = ['8096']
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue20602'
versions = ['Python 2.7', 'Python 3.6', 'Python 3.7', 'Python 3.8']
    @pitrou
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    pitrou commented Feb 11, 2014

    For some reason they are wiped to fix so-called reference leaks:
    http://hg.python.org/cpython/rev/9639a73afa47/

    This changeset is one of the culprits of the problems in bpo-19255.

    @pitrou pitrou added interpreter-core (Objects, Python, Grammar, and Parser dirs) type-bug An unexpected behavior, bug, or error labels Feb 11, 2014
    @vstinner
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    vstinner commented Mar 9, 2015

    I don't understand this bug report. Can you elaborate? What is the current behaviour? What is the expected behaviour?

    @pitrou
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    pitrou commented Mar 9, 2015

    The behaviour is explained in the subject line and in the linked changeset: for some reason sys.flags and sys.float_info are explicitly wiped during shutdown. But those are simple immutable objects, there is no reason to wipe them.

    The expected behaviour is, of course, that those objects keep their proper value during shutdown (e.g. when looked up from destructors).

    @vstinner
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    vstinner commented Mar 9, 2015

    sys_at_exit.py: script to reproduce the issue.

    The changeset 9639a73afa47 explicitly added sys.flags and sys.float_info to sys_deletes, list of symbols that must be cleared at exit.

    So if I understand correctly the issue, the question is why the change was made. Antoine wants to keep these symbols alive during Python shutdown.

    @vstinner
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    vstinner commented Mar 9, 2015

    @antoine: Can you maybe propose a patch to fix this issue?

    I see that you selected Python 3.4 & 3.5. Why Python 3.4 and not 2.7? (Maybe fixing Python 3.5 is enough?)

    @pitrou
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    pitrou commented Mar 9, 2015

    I really don't care about 2.7 for minor fixes is the reason why :-)
    (also, I don't know if the bug exists there in the first place)

    @ZackerySpytz
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    ZackerySpytz mannequin commented Jul 5, 2018

    This behaviour is present in 2.7.

    @ZackerySpytz ZackerySpytz mannequin added 3.7 (EOL) end of life 3.8 only security fixes labels Jul 5, 2018
    @ZackerySpytz
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    ZackerySpytz mannequin commented Dec 9, 2018

    Ping.

    @encukou
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    encukou commented May 30, 2019

    New changeset 249b7d5 by Petr Viktorin (Zackery Spytz) in branch 'master':
    bpo-20602: Do not clear sys.flags and sys.float_info during shutdown (GH-8096)
    249b7d5

    @vstinner
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    vstinner commented Jun 2, 2019

    Honestly, I'm not sure that this issue is really a major bug. I don't think that it's worth it to backport the change. It's more a subtle change in Python finalization which is super fragile code. I prefer to only change the master branch, so I close the issue.

    @vstinner vstinner closed this as completed Jun 2, 2019
    @ezio-melotti ezio-melotti transferred this issue from another repository Apr 10, 2022
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