Update traitlets to 5.1.1 (for python 3.9.8, 3.10)

[EmmanuelCharpentier]

Long story : see sage-support.

TL;DR : On Debian testing, upgrading system Python (to 3.9.8) makes command-line sage crash at startup :

charpent@p-202-021:~$ sage
┌────────────────────────────────────────────────────────────────────┐
│ SageMath version 9.5.beta2, Release Date: 2021-09-26               │
│ Using Python 3.9.8. Type "help()" for help.                        │
└────────────────────────────────────────────────────────────────────┘
┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
┃ Warning: this is a prerelease version, and it may be unstable.     ┃
┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
Traceback (most recent call last):
  File "/usr/local/sage-9/src/bin/sage-ipython", line 15, in <module>
    app.initialize()
  File "/usr/local/sage-9/local/lib/python3.9/site-packages/traitlets/config/application.py", line 88, in inner
    return method(app, *args, **kwargs)
  File "/usr/local/sage-9/local/lib/python3.9/site-packages/IPython/terminal/ipapp.py", line 308, in initialize
    super(TerminalIPythonApp, self).initialize(argv)
  File "/usr/local/sage-9/local/lib/python3.9/site-packages/traitlets/config/application.py", line 88, in inner
    return method(app, *args, **kwargs)
  File "/usr/local/sage-9/local/lib/python3.9/site-packages/IPython/core/application.py", line 450, in initialize
    self.parse_command_line(argv)
  File "/usr/local/sage-9/local/lib/python3.9/site-packages/IPython/terminal/ipapp.py", line 303, in parse_command_line
    return super(TerminalIPythonApp, self).parse_command_line(argv)
  File "/usr/local/sage-9/local/lib/python3.9/site-packages/traitlets/config/application.py", line 88, in inner
    return method(app, *args, **kwargs)
  File "/usr/local/sage-9/local/lib/python3.9/site-packages/traitlets/config/application.py", line 709, in parse_command_line
    self.cli_config = deepcopy(loader.load_config())
  File "/usr/local/sage-9/local/lib/python3.9/site-packages/traitlets/config/loader.py", line 851, in load_config
    self._parse_args(argv)
  File "/usr/local/sage-9/local/lib/python3.9/site-packages/traitlets/config/loader.py", line 908, in _parse_args
    self.parsed_data = self.parser.parse_args(to_parse)
  File "/usr/lib/python3.9/argparse.py", line 1834, in parse_args
    args, argv = self.parse_known_args(args, namespace)
  File "/usr/local/sage-9/local/lib/python3.9/site-packages/traitlets/config/loader.py", line 768, in parse_known_args
    return super().parse_known_args(args, namespace)
  File "/usr/lib/python3.9/argparse.py", line 1862, in parse_known_args
    namespace, args = self._parse_known_args(args, namespace)
  File "/usr/lib/python3.9/argparse.py", line 2076, in _parse_known_args
    start_index = consume_optional(start_index)
  File "/usr/lib/python3.9/argparse.py", line 2016, in consume_optional
    take_action(action, args, option_string)
  File "/usr/lib/python3.9/argparse.py", line 1944, in take_action
    action(self, namespace, argument_values, option_string)
  File "/usr/local/sage-9/local/lib/python3.9/site-packages/traitlets/config/loader.py", line 933, in __call__
    namespace._flags.append(self.flag)
AttributeError: 'Namespace' object has no attribute '_flags'

Neither recompiling IPython nor the whole thing is effective.

Obvious (but painful) workaround :

./configure --with-system-python3=no && make

Component: packages: standard

Author: Matthias Koeppe

Branch/Commit: bbe3f33

Reviewer: Emmanuel Charpentier

Issue created by migration from https://trac.sagemath.org/ticket/32852

[mkoeppe]

Branch: u/mkoeppe/upgrading_system_python_to_3_9_8_makes_command_line_sage_crash_at_startup_

[mkoeppe]

Commit: bbe3f33

[mkoeppe]

comment:2

Please try if this update helps; it is advertised to have fixes for python 3.10, but maybe it helps for 3.9.8 too

---

New commits:

bbe3f33

build/pkgs/traitlets: Update to 5.1.1

[dimpase]

comment:3

SageMath version 9.5.beta2 is old. Can you test with the current beta5 instead?

[EmmanuelCharpentier]

comment:4

Replying to @dimpase:

SageMath version 9.5.beta2 is old. Can you test with the current beta5 instead?

This patch allows Sage 9.5.beta5 to be configured wit system Python at 3.9.8 and run successfully from the command line.

Running ptestlong...

[mkoeppe]

Author: Matthias Koeppe

[EmmanuelCharpentier]

Reviewer: Emmanuel Charpentier

[EmmanuelCharpentier]

comment:6

Replying to @EmmanuelCharpentier:

Replying to @dimpase:

SageMath version 9.5.beta2 is old. Can you test with the current beta5 instead?

This patch allows Sage 9.5.beta5 to be configured wit system Python at 3.9.8 and run successfully from the command line.

Running ptestlong...

Passes ptestlong with no novel problem. ==> positive_review.

A crosscheck on other systems may be useful...

[mkoeppe]

comment:7

Thanks for testing!

[jhpalmieri]

comment:8

Seems necessary on various systems, so it should be a blocker.

[vbraun]

Changed branch from u/mkoeppe/upgrading_system_python_to_3_9_8_makes_command_line_sage_crash_at_startup_ to bbe3f33