***************************************************************************

IPython post-mortem report

{'commit_hash': '9ca5c4454',
 'commit_source': 'installation',
 'default_encoding': 'utf-8',
 'ipython_path': '/usr/lib/python3.9/site-packages/IPython',
 'ipython_version': '7.23.1',
 'os_name': 'posix',
 'platform': 'Linux-5.12.2-arch1-1-x86_64-with-glibc2.33',
 'sys_executable': '/usr/bin/python',
 'sys_platform': 'linux',
 'sys_version': '3.9.5 (default, May  9 2021, 14:00:28) \n[GCC 10.2.0]'}

***************************************************************************



***************************************************************************

Crash traceback:

---------------------------------------------------------------------------
---------------------------------------------------------------------------
ModuleNotFoundError                           Python 3.9.5: /usr/bin/python
                                                   Tue May 11 15:56:21 2021
A problem occurred executing Python code.  Here is the sequence of function
calls leading up to the error, with the most recent (innermost) call last.
/usr/bin/sage-ipython in <module>
      1 #!/usr/bin/python
      2 # -*- coding: utf-8 -*-
      3 """
      4 Sage IPython startup script.
      5 """
      6 
      7 # Display startup banner. Do this before anything else to give the user
      8 # early feedback that Sage is starting.
      9 from sage.misc.banner import banner
     10 banner()
     11 
     12 from sage.repl.interpreter import SageTerminalApp
     13 
     14 app = SageTerminalApp.instance()
---> 15 app.initialize()
        global app.initialize = <bound method TerminalIPythonApp.initialize of <sage.repl.interpreter.SageTerminalApp object at 0x6fee2d82f040>>
     16 app.start()

/usr/lib/python3.9/site-packages/traitlets/config/application.py in inner(app=<sage.repl.interpreter.SageTerminalApp object>, *args=(), **kwargs={})
     72 else:
     73     raise ValueError("Unsupported value for environment variable: 'TRAITLETS_APPLICATION_RAISE_CONFIG_FILE_ERROR' is set to '%s' which is none of  {'0', '1', 'false', 'true', ''}."% _envvar )
     74 
     75 
     76 def catch_config_error(method):
     77     """Method decorator for catching invalid config (Trait/ArgumentErrors) during init.
     78 
     79     On a TraitError (generally caused by bad config), this will print the trait's
     80     message, and exit the app.
     81 
     82     For use on init methods, to prevent invoking excepthook on invalid input.
     83     """
     84     @functools.wraps(method)
     85     def inner(app, *args, **kwargs):
     86         try:
---> 87             return method(app, *args, **kwargs)
        global method = undefined
        app = <sage.repl.interpreter.SageTerminalApp object at 0x6fee2d82f040>
        args = ()
        kwargs = {}
     88         except (TraitError, ArgumentError) as e:
     89             app.log.fatal("Bad config encountered during initialization: %s", e)
     90             app.log.debug("Config at the time: %s", app.config)
     91             app.exit(1)
     92 
     93     return inner
     94 
     95 class ApplicationError(Exception):
     96     pass
     97 
     98 
     99 class LevelFormatter(logging.Formatter):
    100     """Formatter with additional `highlevel` record
    101 
    102     This field is empty if log level is less than highlevel_limit,

/usr/lib/python3.9/site-packages/IPython/terminal/ipapp.py in initialize(self=<sage.repl.interpreter.SageTerminalApp object>, argv=None)
    302 
    303         return super(TerminalIPythonApp, self).parse_command_line(argv)
    304     
    305     @catch_config_error
    306     def initialize(self, argv=None):
    307         """Do actions after construct, but before starting the app."""
    308         super(TerminalIPythonApp, self).initialize(argv)
    309         if self.subapp is not None:
    310             # don't bother initializing further, starting subapp
    311             return
    312         # print self.extra_args
    313         if self.extra_args and not self.something_to_run:
    314             self.file_to_run = self.extra_args[0]
    315         self.init_path()
    316         # create the shell
--> 317         self.init_shell()
        self.init_shell = <bound method SageTerminalApp.init_shell of <sage.repl.interpreter.SageTerminalApp object at 0x6fee2d82f040>>
    318         # and draw the banner
    319         self.init_banner()
    320         # Now a variety of things that happen after the banner is printed.
    321         self.init_gui_pylab()
    322         self.init_extensions()
    323         self.init_code()
    324 
    325     def init_shell(self):
    326         """initialize the InteractiveShell instance"""
    327         # Create an InteractiveShell instance.
    328         # shell.display_banner should always be False for the terminal
    329         # based app, because we call shell.show_banner() by hand below
    330         # so the banner shows *before* all extension loading stuff.
    331         self.shell = self.interactive_shell_class.instance(parent=self,
    332                         profile_dir=self.profile_dir,

/usr/lib/python3.9/site-packages/sage/repl/interpreter.py in init_shell(self=<sage.repl.interpreter.SageTerminalApp object>)
    766         Initialize the :class:`SageInteractiveShell` instance.
    767 
    768         .. note::
    769 
    770             This code is based on
    771             :meth:`TerminalIPythonApp.init_shell`.
    772 
    773         EXAMPLES::
    774 
    775             sage: from sage.repl.interpreter import SageTerminalApp
    776             sage: app = SageTerminalApp.instance()
    777             sage: app.shell
    778             <sage.repl.interpreter.SageTestShell object at 0x...>
    779         """
    780         # Shell initialization
--> 781         self.shell = self.shell_class.instance(
        self.shell = None
        self.shell_class.instance = <bound method SingletonConfigurable.instance of <class 'sage.repl.interpreter.SageTerminalInteractiveShell'>>
        global parent = undefined
        self = <sage.repl.interpreter.SageTerminalApp object at 0x6fee2d82f040>
        global config = undefined
        self.config = {'TerminalIPythonApp': {'display_banner': False, 'verbose_crash': True, 'test_shell': False, 'shell_class': <class 'sage.repl.interpreter.SageTerminalInteractiveShell'>}, 'InteractiveShell': {'prompts_class': <class 'sage.repl.prompts.SagePrompts'>, 'ast_node_interactivity': 'all', 'colors': 'LightBG', 'simple_prompt': False, 'term_title': True, 'confirm_exit': False, 'separate_in': ''}, 'TerminalInteractiveShell': {'prompts_class': <class 'sage.repl.prompts.SagePrompts'>, 'ast_node_interactivity': 'all', 'colors': 'LightBG', 'simple_prompt': False, 'term_title': True, 'confirm_exit': False, 'separate_in': ''}, 'InteractiveShellApp': {'extensions': ['sage']}, 'IPCompleter': {'use_jedi': False}, 'SageTerminalApp': {'force_interact': True}}
        global profile_dir = undefined
        self.profile_dir = <IPython.core.profiledir.ProfileDir object at 0x6fee2d82ff40>
        global ipython_dir = undefined
        self.ipython_dir = '/home/$USER/.sage/ipython-5.0.0'
    782             parent=self,
    783             config=self.config,
    784             profile_dir=self.profile_dir,
    785             ipython_dir=self.ipython_dir)
    786         self.shell.configurables.append(self)
    787         self.shell.has_sage_extensions = SAGE_EXTENSION in self.extensions
    788 
    789         # Load the %lprun extension if available
    790         try:
    791             import line_profiler
    792             assert line_profiler  # silence pyflakes
    793         except ImportError:
    794             pass
    795         else:
    796             self.extensions.append('line_profiler')

/usr/lib/python3.9/site-packages/traitlets/config/configurable.py in
instance(cls=<class 'sage.repl.interpreter.SageTerminalInteractiveShell'>,
*args=(), **kwargs={'config': {'TerminalIPythonApp': {'display_banner':
False,...se}, 'SageTerminalApp': {'force_interact': True}}, 'ipython_dir': '/home/$USER/.sage/ipython-5.0.0', 'parent': <sage.repl.interpreter.SageTerminalApp object>, 'profile_dir': <IPython.core.profiledir.ProfileDir object>})
    522             >>> class Foo(SingletonConfigurable): pass
    523             >>> foo = Foo.instance()
    524             >>> foo == Foo.instance()
    525             True
    526 
    527         Create a subclass that is retrived using the base class instance::
    528 
    529             >>> class Bar(SingletonConfigurable): pass
    530             >>> class Bam(Bar): pass
    531             >>> bam = Bam.instance()
    532             >>> bam == Bar.instance()
    533             True
    534         """
    535         # Create and save the instance
    536         if cls._instance is None:
--> 537             inst = cls(*args, **kwargs)
        inst = undefined
        cls = <class 'sage.repl.interpreter.SageTerminalInteractiveShell'>
        args = ()
        kwargs = {'parent': <sage.repl.interpreter.SageTerminalApp object at 0x6fee2d82f040>, 'config': {'TerminalIPythonApp': {'display_banner': False, 'verbose_crash': True, 'test_shell': False, 'shell_class': <class 'sage.repl.interpreter.SageTerminalInteractiveShell'>}, 'InteractiveShell': {'prompts_class': <class 'sage.repl.prompts.SagePrompts'>, 'ast_node_interactivity': 'all', 'colors': 'LightBG', 'simple_prompt': False, 'term_title': True, 'confirm_exit': False, 'separate_in': ''}, 'TerminalInteractiveShell': {'prompts_class': <class 'sage.repl.prompts.SagePrompts'>, 'ast_node_interactivity': 'all', 'colors': 'LightBG', 'simple_prompt': False, 'term_title': True, 'confirm_exit': False, 'separate_in': ''}, 'InteractiveShellApp': {'extensions': ['sage']}, 'IPCompleter': {'use_jedi': False}, 'SageTerminalApp': {'force_interact': True}}, 'profile_dir': <IPython.core.profiledir.ProfileDir object at 0x6fee2d82ff40>, 'ipython_dir': '/home/$USER/.sage/ipython-5.0.0'}
    538             # Now make sure that the instance will also be returned by
    539             # parent classes' _instance attribute.
    540             for subclass in cls._walk_mro():
    541                 subclass._instance = inst
    542 
    543         if isinstance(cls._instance, cls):
    544             return cls._instance
    545         else:
    546             raise MultipleInstanceError(
    547                 "An incompatible sibling of '%s' is already instanciated"
    548                 " as singleton: %s" % (cls.__name__, type(cls._instance).__name__)
    549             )
    550 
    551     @classmethod
    552     def initialized(cls):

/usr/lib/python3.9/site-packages/IPython/terminal/interactiveshell.py in __init__(self=<sage.repl.interpreter.SageTerminalInteractiveShell object>, *args=(), **kwargs={'config': {'TerminalIPythonApp': {'display_banner': False,...se}, 'SageTerminalApp': {'force_interact': True}}, 'ipython_dir': '/home/$USER/.sage/ipython-5.0.0', 'parent': <sage.repl.interpreter.SageTerminalApp object>, 'profile_dir': <IPython.core.profiledir.ProfileDir object>})
    510 
    511     def init_alias(self):
    512         # The parent class defines aliases that can be safely used with any
    513         # frontend.
    514         super(TerminalInteractiveShell, self).init_alias()
    515 
    516         # Now define aliases that only make sense on the terminal, because they
    517         # need direct access to the console in a way that we can't emulate in
    518         # GUI or web frontend
    519         if os.name == 'posix':
    520             for cmd in ('clear', 'more', 'less', 'man'):
    521                 self.alias_manager.soft_define_alias(cmd, cmd)
    522 
    523 
    524     def __init__(self, *args, **kwargs):
--> 525         super(TerminalInteractiveShell, self).__init__(*args, **kwargs)
        global super = undefined
        global TerminalInteractiveShell = <class 'IPython.terminal.interactiveshell.TerminalInteractiveShell'>
        self.__init__ = <bound method TerminalInteractiveShell.__init__ of <sage.repl.interpreter.SageTerminalInteractiveShell object at 0x6fee2cd54f10>>
        args = ()
        kwargs = {'parent': <sage.repl.interpreter.SageTerminalApp object at 0x6fee2d82f040>, 'config': {'TerminalIPythonApp': {'display_banner': False, 'verbose_crash': True, 'test_shell': False, 'shell_class': <class 'sage.repl.interpreter.SageTerminalInteractiveShell'>}, 'InteractiveShell': {'prompts_class': <class 'sage.repl.prompts.SagePrompts'>, 'ast_node_interactivity': 'all', 'colors': 'LightBG', 'simple_prompt': False, 'term_title': True, 'confirm_exit': False, 'separate_in': ''}, 'TerminalInteractiveShell': {'prompts_class': <class 'sage.repl.prompts.SagePrompts'>, 'ast_node_interactivity': 'all', 'colors': 'LightBG', 'simple_prompt': False, 'term_title': True, 'confirm_exit': False, 'separate_in': ''}, 'InteractiveShellApp': {'extensions': ['sage']}, 'IPCompleter': {'use_jedi': False}, 'SageTerminalApp': {'force_interact': True}}, 'profile_dir': <IPython.core.profiledir.ProfileDir object at 0x6fee2d82ff40>, 'ipython_dir': '/home/$USER/.sage/ipython-5.0.0'}
    526         self.init_prompt_toolkit_cli()
    527         self.init_term_title()
    528         self.keep_running = True
    529 
    530         self.debugger_history = InMemoryHistory()
    531 
    532     def ask_exit(self):
    533         self.keep_running = False
    534 
    535     rl_next_input = None
    536 
    537     def interact(self, display_banner=DISPLAY_BANNER_DEPRECATED):
    538 
    539         if display_banner is not DISPLAY_BANNER_DEPRECATED:
    540             warn('interact `display_banner` argument is deprecated since IPython 5.0. Call `show_banner()` if needed.', DeprecationWarning, stacklevel=2)

/usr/lib/python3.9/site-packages/IPython/core/interactiveshell.py in __init__(self=<sage.repl.interpreter.SageTerminalInteractiveShell object>, ipython_dir='/home/$USER/.sage/ipython-5.0.0', profile_dir=<IPython.core.profiledir.ProfileDir object>, user_module=None, user_ns=None, custom_exceptions=((), None), **kwargs={'config': {'TerminalIPythonApp': {'display_banner': False,...se}, 'SageTerminalApp': {'force_interact': True}}, 'parent': <sage.repl.interpreter.SageTerminalApp object>})
    669         self.init_pushd_popd_magic()
    670         self.init_user_ns()
    671         self.init_logger()
    672         self.init_builtins()
    673 
    674         # The following was in post_config_initialization
    675         self.init_inspector()
    676         self.raw_input_original = input
    677         self.init_completer()
    678         # TODO: init_io() needs to happen before init_traceback handlers
    679         # because the traceback handlers hardcode the stdout/stderr streams.
    680         # This logic in in debugger.Pdb and should eventually be changed.
    681         self.init_io()
    682         self.init_traceback_handlers(custom_exceptions)
    683         self.init_prompts()
--> 684         self.init_display_formatter()
        self.init_display_formatter = <bound method SageTerminalInteractiveShell.init_display_formatter of <sage.repl.interpreter.SageTerminalInteractiveShell object at 0x6fee2cd54f10>>
    685         self.init_display_pub()
    686         self.init_data_pub()
    687         self.init_displayhook()
    688         self.init_magics()
    689         self.init_alias()
    690         self.init_logstart()
    691         self.init_pdb()
    692         self.init_extension_manager()
    693         self.init_payload()
    694         self.init_deprecation_warnings()
    695         self.hooks.late_startup_hook()
    696         self.events.trigger('shell_initialized', self)
    697         atexit.register(self.atexit_operations)
    698 
    699         # The trio runner is used for running Trio in the foreground thread. It

/usr/lib/python3.9/site-packages/sage/repl/interpreter.py in init_display_formatter(self=<sage.repl.interpreter.SageTerminalInteractiveShell object>)
    289         sage: SageTerminalInteractiveShell()   # not tested
    290         <sage.repl.interpreter.SageNotebookInteractiveShell object at 0x...>
    291     """
    292 
    293     def init_display_formatter(self):
    294         """
    295         Switch to the Sage IPython commandline rich output backend
    296 
    297         EXAMPLES::
    298 
    299             sage: from sage.repl.interpreter import SageTerminalInteractiveShell
    300             sage: SageTerminalInteractiveShell().init_display_formatter()   # not tested
    301         """
    302         from sage.repl.rich_output.backend_ipython import BackendIPythonCommandline
    303         backend = BackendIPythonCommandline()
--> 304         backend.get_display_manager().switch_backend(backend, shell=self)
        backend.get_display_manager.switch_backend = undefined
        backend = IPython command line
        global shell = undefined
        self = <sage.repl.interpreter.SageTerminalInteractiveShell object at 0x6fee2cd54f10>
    305 
    306 
    307 class SageTestShell(SageShellOverride, TerminalInteractiveShell):
    308     """
    309     Test Shell
    310 
    311     Care must be taken in these doctests to quit the test shell in
    312     order to switch back the rich output display backend to the
    313     doctest backend.
    314 
    315     EXAMPLES::
    316 
    317         sage: from sage.repl.interpreter import get_test_shell
    318         sage: shell = get_test_shell();  shell
    319         <sage.repl.interpreter.SageTestShell object at 0x...>

/usr/lib/python3.9/site-packages/sage/repl/rich_output/display_manager.py in switch_backend(self=The Sage display manager using the IPython command line backend, backend=IPython command line, **kwds={'shell': <sage.repl.interpreter.SageTerminalInteractiveShell object>})
    310             raise ValueError('every backend must support plain text')
    311         try:
    312             self._backend.uninstall()
    313         except AttributeError:
    314             pass   # first time we switch
    315         # clear caches
    316         self._output_promotions = dict()
    317         self._supported_output = frozenset(
    318             map(self._demote_output_class, backend.supported_output()))
    319         # install new backend
    320         try:
    321             old_backend = self._backend
    322         except AttributeError:
    323             old_backend = None
    324         self._backend = backend
--> 325         self._backend.install(**kwds)
        self._backend.install = <bound method BackendIPython.install of IPython command line>
        kwds = {'shell': <sage.repl.interpreter.SageTerminalInteractiveShell object at 0x6fee2cd54f10>}
    326         self._preferences = DisplayPreferences(self._backend.default_preferences())
    327         return old_backend
    328 
    329     @property
    330     def preferences(self):
    331         """
    332         Return the preferences.
    333 
    334         OUTPUT:
    335 
    336         The display preferences as instance of
    337         :class:`~sage.repl.rich_output.preferences.DisplayPreferences`.
    338 
    339         EXAMPLES::
    340 

/usr/lib/python3.9/site-packages/sage/repl/rich_output/backend_ipython.py in install(self=IPython command line, **kwds={'shell': <sage.repl.interpreter.SageTerminalInteractiveShell object>})
     45 
     46         No tests since switching away from the doctest rich output
     47         backend will break the doctests.
     48 
     49         EXAMPLES::
     50 
     51             sage: from sage.repl.interpreter import get_test_shell
     52             sage: from sage.repl.rich_output.backend_ipython import BackendIPython
     53             sage: backend = BackendIPython()
     54             sage: shell = get_test_shell()
     55             sage: backend.install(shell=shell)
     56             sage: shell.run_cell('1+1')
     57             2
     58         """
     59         shell = kwds['shell']
---> 60         from sage.repl.display.formatter import SageDisplayFormatter
        global sage.repl.display.formatter = undefined
        SageDisplayFormatter = undefined
     61         shell.display_formatter = SageDisplayFormatter(parent=shell)
     62         shell.configurables.append(shell.display_formatter)
     63 
     64     def set_underscore_variable(self, obj):
     65         """
     66         Set the ``_`` builtin variable.
     67 
     68         Since IPython handles the history itself, this does nothing.
     69 
     70         INPUT:
     71 
     72         - ``obj`` -- anything.
     73 
     74         EXAMPLES::
     75 

/usr/lib/python3.9/site-packages/sage/repl/display/formatter.py in <module>
     54 # ****************************************************************************
     55 #       Copyright (C) 2014 Volker Braun <vbraun.name@gmail.com>
     56 #
     57 #  Distributed under the terms of the GNU General Public License (GPL)
     58 #  as published by the Free Software Foundation; either version 2 of
     59 #  the License, or (at your option) any later version.
     60 #                  https://www.gnu.org/licenses/
     61 # ****************************************************************************
     62 
     63 from io import StringIO
     64 
     65 from IPython.core.formatters import DisplayFormatter, PlainTextFormatter
     66 from IPython.utils.py3compat import unicode_to_str
     67 from IPython.core.display import DisplayObject
     68 
---> 69 from ipywidgets.widgets.interaction import interactive
        global ipywidgets.widgets.interaction = undefined
        global interactive = undefined
     70 
     71 from sage.repl.display.pretty_print import SagePrettyPrinter
     72 
     73 IPYTHON_NATIVE_TYPES = (DisplayObject, interactive)
     74 
     75 PLAIN_TEXT = 'text/plain'
     76 TEXT_LATEX = 'text/latex'
     77 TEXT_HTML = 'text/html'
     78 
     79 
     80 class SageDisplayFormatter(DisplayFormatter):
     81 
     82     def __init__(self, *args, **kwds):
     83         """
     84         This is where the Sage rich objects are translated to IPython

ModuleNotFoundError: No module named 'ipywidgets'

***************************************************************************

History of session input: