René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Bug]: crash due to backend issue in ipython session started explicitly with InteractiveShell ","articleBody":"### Bug summary\n\nIf an IPython session is started via `IPython.core.interactiveshell.InteractiveShell.instance()`, trying to create a matplotlib figure, or even query the backend, produces a crash (stack trace below) on OS X, and on Linux if there is an active X11 session.\r\n\r\nWithout an X session on Linux or if ipython is started via the command-line `ipython` command, everything works as expected.\n\n### Code for reproduction\n\n```python\nimport IPython.core.interactiveshell\r\nIPython.core.interactiveshell.InteractiveShell.instance()\r\n\r\nimport matplotlib.pyplot\r\nmatplotlib.pyplot.figure()\r\n# or the below crashes too\r\nimport matplotlib\r\nmatplotlib.get_backend()\n```\n\n\n### Actual outcome\n\n```\r\nIn : matplotlib.pyplot.figure()\r\nTraceback (most recent call last):\r\n  File \"\u003cstdin\u003e\", line 1, in \u003cmodule\u003e\r\n  File \"/Users/zpincus/miniconda/envs/mplcrash/lib/python3.10/site-packages/matplotlib/pyplot.py\", line 806, in figure\r\n    manager = new_figure_manager(\r\n  File \"/Users/zpincus/miniconda/envs/mplcrash/lib/python3.10/site-packages/matplotlib/pyplot.py\", line 324, in new_figure_manager\r\n    _warn_if_gui_out_of_main_thread()\r\n  File \"/Users/zpincus/miniconda/envs/mplcrash/lib/python3.10/site-packages/matplotlib/pyplot.py\", line 314, in _warn_if_gui_out_of_main_thread\r\n    if (_get_required_interactive_framework(_get_backend_mod())\r\n  File \"/Users/zpincus/miniconda/envs/mplcrash/lib/python3.10/site-packages/matplotlib/pyplot.py\", line 217, in _get_backend_mod\r\n    switch_backend(dict.__getitem__(rcParams, \"backend\"))\r\n  File \"/Users/zpincus/miniconda/envs/mplcrash/lib/python3.10/site-packages/matplotlib/pyplot.py\", line 262, in switch_backend\r\n    switch_backend(candidate)\r\n  File \"/Users/zpincus/miniconda/envs/mplcrash/lib/python3.10/site-packages/matplotlib/pyplot.py\", line 310, in switch_backend\r\n    install_repl_displayhook()\r\n  File \"/Users/zpincus/miniconda/envs/mplcrash/lib/python3.10/site-packages/matplotlib/pyplot.py\", line 150, in install_repl_displayhook\r\n    ip.enable_gui(ipython_gui_name)\r\n  File \"/Users/zpincus/miniconda/envs/mplcrash/lib/python3.10/site-packages/IPython/core/interactiveshell.py\", line 3455, in enable_gui\r\n    raise NotImplementedError('Implement enable_gui in a subclass')\r\nNotImplementedError: Implement enable_gui in a subclass\r\n\r\n```\n\n### Expected outcome\n\n```\r\nIn : matplotlib.pyplot.figure()\r\n\u003cFigure size 640x480 with 0 Axes\u003e\r\n```\n\n### Additional information\n\nThe below is sufficient to reproduce the crash from a clean environment. \r\n```\r\nconda create -n \"mplcrash\" -c conda-forge python=3.10 matplotlib ipython\r\nconda activate mplcrash\r\npython -c 'import IPython.core.interactiveshell as ipsh; ipsh.InteractiveShell.instance(); import matplotlib.pyplot as plt; plt.figure()'\r\n```\r\n\r\nIt's a weird corner case to be creating an ipython session this way, and perhaps the problem is on my end, but I wasn't expecting a crash like this regardless...\n\n### Operating system\n\nmacOS, Linux, maybe windows too?\n\n### Matplotlib Version\n\n3.5.3\n\n### Matplotlib Backend\n\nthis crashes too with the same error when invoked after starting `InteractiveShell.instance()` \n\n### Python version\n\n3.10.6 (but also occurs with various 3.9 versions)\n\n### Jupyter version\n\n_No response_\n\n### Installation\n\nconda","author":{"url":"https://github.com/zpincus","@type":"Person","name":"zpincus"},"datePublished":"2022-08-29T20:16:52.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":11},"url":"https://github.com/23770/matplotlib/issues/23770"}