streamhandler cannot represent streams with an integer as name

[xrmx]

BPO	36015
Nosy	@vsajip, @ronaldoussoren, @xrmx
PRs	bpo-36015: logging: handle StreamHandler representaton of stream with int name #11908 [3.7] bpo-36015: Handle StreamHandler representaton of stream with an integer name (GH-11908) #13183

^{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 2019-05-15.18:41:32.541>
created_at = <Date 2019-02-17.19:20:24.118>
labels = ['3.7', '3.8', 'type-bug', 'library']
title = 'streamhandler cannot represent streams with an integer as name'
updated_at = <Date 2019-05-15.18:41:32.541>
user = 'https://github.com/xrmx'

bugs.python.org fields:

activity = <Date 2019-05-15.18:41:32.541>
actor = 'vinay.sajip'
assignee = 'none'
closed = True
closed_date = <Date 2019-05-15.18:41:32.541>
closer = 'vinay.sajip'
components = ['Library (Lib)']
creation = <Date 2019-02-17.19:20:24.118>
creator = 'Riccardo Magliocchetti'
dependencies = []
files = []
hgrepos = []
issue_num = 36015
keywords = ['patch']
message_count = 11.0
messages = ['335784', '335814', '335819', '335822', '335843', '335868', '337207', '337362', '341766', '341832', '342590']
nosy_count = 3.0
nosy_names = ['vinay.sajip', 'ronaldoussoren', 'Riccardo Magliocchetti']
pr_nums = ['11908', '13183']
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue36015'
versions = ['Python 3.7', 'Python 3.8']

[xrmx]

When debugging uwsgi logging issues with python3.7 i got this on python 3.7.2:
Traceback (most recent call last):
  File "/usr/lib/python3.7/logging/__init__.py", line 269, in _after_at_fork_weak_calls
    _at_fork_weak_calls('release')
  File "/usr/lib/python3.7/logging/__init__.py", line 261, in _at_fork_weak_calls
    method_name, "method:", err, file=sys.stderr)
  File "/usr/lib/python3.7/logging/__init__.py", line 1066, in __repr__
    name = name + ' '
TypeError: unsupported operand type(s) for +: 'int' and 'str'

AFAICS uwsgi creates sys.stderr as an unbuffered file with PyFile_FromFd() and sets it to sys dict.

[vsajip]

I'm not sure this is a problem with logging. The code immediately preceding the failure is:

    name = getattr(self.stream, 'name', '')
    if name:
        name += ' '

So, the failure occurs because the stream has a name attribute which is not a string. Even if sys.stderr itself is an unbuffered file, why is its 'name' attribute not a string? I don't imagine the name would be actually used for I/O, and having it set to an integer is a surprise.

I propose to close this (and the associated PR) unless a good reason is given why we have to support non-string names here.

[xrmx]

Yeah, I'm not sure the pr is just papering over the real issue :) Need to check what io.open sets on name. IF it setting the fd as name instead of creating a string that would be still be a bug in Python to me. Could you please wait a bit for me to check that before closing?

[ronaldoussoren]

In Python 3.7.2:

>>> open(2, 'a')
<_io.TextIOWrapper name=2 mode='a' encoding='UTF-8'>
>>> m = _
>>> m.name
2
>>> type(_)
<class 'int'>

That is, when opening a file descriptor the name is set to the value of that file descriptor as an integer.

BTW. The implementation of PyFile_FromFd is a thin wrapper around the open function.

[vsajip]

That is, when opening a file descriptor the name is set to the value of that file descriptor as an integer.

I see. But I wonder if there is anything that relies on the name being an integer? It seems pretty counter-intuitive for a 'name' attribute to be set to something other than a string.

[xrmx]

Looking at Modules/_io/fileio.c::_io_FileIO___init___impl it seems an int for nameobj is just fine. Not sure I am looking at the right code though :)

[xrmx]

@vinay Do you have any update on this? thanks

[vsajip]

Sorry, Riccardo, been very busy lately and not had time to look at it :-( Soon, I hope.

[xrmx]

Friendly ping, would be helpful to get this resolved for 3.8.0. Thanks!

[vsajip]

New changeset ca87eeb by Vinay Sajip (Riccardo Magliocchetti) in branch 'master':
bpo-36015: Handle StreamHandler representaton of stream with an integer name (GH-11908)
ca87eeb

[vsajip]

New changeset 78dd781 by Vinay Sajip (Miss Islington (bot)) in branch '3.7':
bpo-36015: Handle StreamHandler representaton of stream with an integer name (GH-11908) (GH-13183)
78dd781