{"record":{"id":"7e23504fa8a4a72b","repo":"matplotlib/matplotlib","slug":"backend-is-not-a-recognised-backend-name","errorCode":null,"errorMessage":"'{backend}' is not a recognised backend name","messagePattern":"'(.+?)' is not a recognised backend name","errorType":"exception","errorClass":"RuntimeError","httpStatus":null,"severity":"error","filePath":"lib/matplotlib/backends/registry.py","lineNumber":369,"sourceCode":"        gui = (self._BUILTIN_BACKEND_TO_GUI_FRAMEWORK.get(backend) or\n               self._backend_to_gui_framework.get(backend))\n\n        # Is backend \"module://something\"?\n        if gui is None and isinstance(backend, str) and backend.startswith(\"module://\"):\n            gui = \"unknown\"\n\n        # Is backend a possible entry point?\n        if gui is None and not self._loaded_entry_points:\n            self._ensure_entry_points_loaded()\n            gui = self._backend_to_gui_framework.get(backend)\n\n        # Backend known but not its gui framework.\n        if gui == \"unknown\":\n            gui = self._get_gui_framework_by_loading(backend)\n            self._backend_to_gui_framework[backend] = gui\n\n        if gui is None:\n            raise RuntimeError(f\"'{backend}' is not a recognised backend name\")\n\n        return backend, gui if gui != \"headless\" else None\n\n    def resolve_gui_or_backend(self, gui_or_backend):\n        \"\"\"\n        Return the backend and GUI framework for the specified string that may be\n        either a GUI framework or a backend name, tested in that order.\n\n        This is for use with the IPython %matplotlib magic command which may be a GUI\n        framework such as ``%matplotlib qt`` or a backend name such as\n        ``%matplotlib qtagg``.\n\n        This function only loads entry points if they have not already been loaded and\n        the backend is not built-in and not of ``module://some.backend`` format.\n\n        Parameters\n        ----------\n        gui_or_backend : str or None","sourceCodeStart":351,"sourceCodeEnd":387,"githubUrl":"https://github.com/matplotlib/matplotlib/blob/b379c1b69e012b142c0f496a52bcb30513802d72/lib/matplotlib/backends/registry.py#L351-L387","documentation":"Error \"'{backend}' is not a recognised backend name\" thrown in matplotlib/matplotlib.","triggerScenarios":"Thrown at lib/matplotlib/backends/registry.py:369 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":[],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"b379c1b69e012b142c0f496a52bcb30513802d72","analyzedAt":"2026-08-21T23:31:55.468Z","schemaVersion":2},"datasetVersion":"2026-08-22T04:17:13.399Z"}